MCP zephyr_get_test_case output schema to allow additionalProperties: true

[7HemiCuda1]

Component: SmartBear Zephyr MCP Server
Affected Tool: zephyr_get_test_case
Severity: High (blocks all tool usage)
Date: January 27, 2026
Summary
The zephyr_get_test_case tool fails with MCP error -32602 due to output schema validation rejecting additional properties returned by the Zephyr Scale API.
Steps to Reproduce
Call zephyr_get_test_case with a valid test case key
Example parameters:
{
"testCaseKey": "SQA-T35013"
}
{ "testCaseKey": "SQA-T35013" }
Actual Result
MCP error -32602: Structured content does not match the tool's output schema:
data/project must NOT have additional properties,
data/project must NOT have additional properties,
data/priority must NOT have additional properties,
data/priority must NOT have additional properties,
data/status must NOT have additional properties,
data/status must NOT have additional properties,
data/folder must NOT have additional properties,
data/folder must NOT have additional properties,
data/folder must be null,
data/folder must match a schema in anyOf,
data/links must NOT have additional properties,
data/links must NOT have additional properties,
data/links must NOT have additional properties

MCP error -32602: Structured content does not match the tool's output schema: data/project must NOT have additional properties, data/project must NOT have additional properties, data/priority must NOT have additional properties, data/priority must NOT have additional properties, data/status must NOT have additional properties, data/status must NOT have additional properties, data/folder must NOT have additional properties, data/folder must NOT have additional properties, data/folder must be null, data/folder must match a schema in anyOf, data/links must NOT have additional properties, data/links must NOT have additional properties, data/links must NOT have additional properties

Expected Result
The tool should return the test case data successfully.

Root Cause Analysis
The MCP tool's output schema appears to have additionalProperties: false set on the following objects:
project
priority
status
folder
links
This causes JSON Schema validation to fail even though the API response is valid.

Solution:
Set additionalProperties: true on the affected object schemas to allow for API evolution

MCP Server: smartbear (Zephyr Scale integration)
Tool: zephyr_get_test_case
Zephyr Scale API: Cloud version
Workaround:
Currently using direct REST API calls to Zephyr Scale, bypassing the MCP tool entirely.

[adrienave]

Hello @7HemiCuda1 ,
I'm Adrien, a SmartBear software engineer working on Zephyr.

Unfortunately, I'm not able to reproduce the issue, either on dev or prod environment.

It would be nice to get more insights about your context to investigate this deeper (what is inside of SQA-T35013, what are you getting from directly calling the REST API get endpoint, how are you using the MCP server etc.)

I invite you to create a support ticket with SmartBear through this portal: https://support.smartbear.com/zephyr-scale/message/
There you will be able to share all your data in a secured way, and I will be able to give you the support you require.

[7HemiCuda1]

thanks for looking into this, here is the additional info you requested. (I reviewed to ensure there is no sensitive data in the test case and response.)

I am just asking the mcp to get the test cases, the

here is the test case.
{ "id": 294678793, "projectId": 10040, "name": "Verify Zephyr test step actualResult is empty for passing steps", "key": "SQA-T35013", "majorVersion": 1, "owner": "602406929887580068927c29", "objective": "validating the Playwright Zephyr Integration", "createdBy": "602406929887580068927c29", "createdOn": "2026-01-27T22:46:09Z", "statusId": 9466229, "priorityId": 9466381, "folderId": 30444418, "testScript": { "stepByStepScript": { "id": 477510669, "steps": [ { "id": 2212356607, "index": 0, "description": "<div style='color: rgb(228, 228, 228); background-color: rgb(24, 24, 24); font-family: Menlo, Monaco, \"Courier New\", monospace; font-weight: normal; font-size: 12px; line-height: 18px; white-space: pre; --darkreader-inline-color: var(--darkreader-text-e4e4e4, #d7d3ce); --darkreader-inline-bgcolor: var(--darkreader-background-181818, #121414);' data-pasted=\"true\" data-darkreader-inline-color=\"\" data-darkreader-inline-bgcolor=\"\"><span style=\"color: rgb(227, 148, 220); --darkreader-inline-color: var(--darkreader-text-e394dc, #e18cd9);\" data-darkreader-inline-color=\"\">Get authorization token from vault</span></div>", "testData": null, "expectedResult": "", "testCase": null, "userHasAccessToTestCase": null, "stepParameters": [], "customFieldValues": [], "attachments": [], "reflectRef": null }, { "id": 2212356608, "index": 1, "description": "<div style='color: rgb(228, 228, 228); background-color: rgb(24, 24, 24); font-family: Menlo, Monaco, \"Courier New\", monospace; font-weight: normal; font-size: 12px; line-height: 18px; white-space: pre; --darkreader-inline-color: var(--darkreader-text-e4e4e4, #d7d3ce); --darkreader-inline-bgcolor: var(--darkreader-background-181818, #121414);' data-pasted=\"true\" data-darkreader-inline-color=\"\" data-darkreader-inline-bgcolor=\"\"><span style=\"color: rgb(227, 148, 220); --darkreader-inline-color: var(--darkreader-text-e394dc, #e18cd9);\" data-darkreader-inline-color=\"\">Query Zephyr for last execution of</span></div>", "testData": null, "expectedResult": null, "testCase": null, "userHasAccessToTestCase": null, "stepParameters": [], "customFieldValues": [], "attachments": [], "reflectRef": null }, { "id": 2212411336, "index": 2, "description": "<div style='color: rgb(228, 228, 228); background-color: rgb(24, 24, 24); font-family: Menlo, Monaco, \"Courier New\", monospace; font-weight: normal; font-size: 12px; line-height: 18px; white-space: pre; --darkreader-inline-color: var(--darkreader-text-e4e4e4, #d7d3ce); --darkreader-inline-bgcolor: var(--darkreader-background-181818, #121414);' data-pasted=\"true\" data-darkreader-inline-color=\"\" data-darkreader-inline-bgcolor=\"\"><span style=\"color: rgb(227, 148, 220); --darkreader-inline-color: var(--darkreader-text-e394dc, #e18cd9);\" data-darkreader-inline-color=\"\">Verify execution ran within the last 10 minutes</span></div>", "testData": null, "expectedResult": null, "testCase": null, "userHasAccessToTestCase": null, "stepParameters": [], "customFieldValues": [], "attachments": [], "reflectRef": null }, { "id": 2212411486, "index": 3, "description": "<div style='color: rgb(228, 228, 228); background-color: rgb(24, 24, 24); font-family: Menlo, Monaco, \"Courier New\", monospace; font-weight: normal; font-size: 12px; line-height: 18px; white-space: pre; --darkreader-inline-color: var(--darkreader-text-e4e4e4, #d7d3ce); --darkreader-inline-bgcolor: var(--darkreader-background-181818, #121414);' data-pasted=\"true\" data-darkreader-inline-color=\"\" data-darkreader-inline-bgcolor=\"\"><span style=\"color: rgb(227, 148, 220); --darkreader-inline-color: var(--darkreader-text-e394dc, #e18cd9);\" data-darkreader-inline-color=\"\">Get test script results (steps) from execution</span></div>", "testData": null, "expectedResult": null, "testCase": null, "userHasAccessToTestCase": null, "stepParameters": [], "customFieldValues": [], "attachments": [], "reflectRef": null }, { "id": 2212411681, "index": 4, "description": "<div style='color: rgb(228, 228, 228); background-color: rgb(24, 24, 24); font-family: Menlo, Monaco, \"Courier New\", monospace; font-weight: normal; font-size: 12px; line-height: 18px; white-space: pre; --darkreader-inline-color: var(--darkreader-text-e4e4e4, #d7d3ce); --darkreader-inline-bgcolor: var(--darkreader-background-181818, #121414);' data-pasted=\"true\" data-darkreader-inline-color=\"\" data-darkreader-inline-bgcolor=\"\"><span style=\"color: rgb(227, 148, 220); --darkreader-inline-color: var(--darkreader-text-e394dc, #e18cd9);\" data-darkreader-inline-color=\"\">Verify test steps match expected test.step() calls</span></div>", "testData": null, "expectedResult": null, "testCase": null, "userHasAccessToTestCase": null, "stepParameters": [], "customFieldValues": [], "attachments": [], "reflectRef": null }, { "id": 2212411707, "index": 5, "description": "<div style='color: rgb(228, 228, 228); background-color: rgb(24, 24, 24); font-family: Menlo, Monaco, \"Courier New\", monospace; font-weight: normal; font-size: 12px; line-height: 18px; white-space: pre; --darkreader-inline-color: var(--darkreader-text-e4e4e4, #d7d3ce); --darkreader-inline-bgcolor: var(--darkreader-background-181818, #121414);' data-pasted=\"true\" data-darkreader-inline-color=\"\" data-darkreader-inline-bgcolor=\"\"><span style=\"color: rgb(227, 148, 220); --darkreader-inline-color: var(--darkreader-text-e394dc, #e18cd9);\" data-darkreader-inline-color=\"\">Verify actualResult is empty for passing steps (Zephyr best practice)</span></div>", "testData": null, "expectedResult": null, "testCase": null, "userHasAccessToTestCase": null, "stepParameters": [], "customFieldValues": [], "attachments": [], "reflectRef": null }, { "id": 2212411828, "index": 6, "description": "<div style='color: rgb(228, 228, 228); background-color: rgb(24, 24, 24); font-family: Menlo, Monaco, \"Courier New\", monospace; font-weight: normal; font-size: 12px; line-height: 18px; white-space: pre; --darkreader-inline-color: var(--darkreader-text-e4e4e4, #d7d3ce); --darkreader-inline-bgcolor: var(--darkreader-background-181818, #121414);' data-pasted=\"true\" data-darkreader-inline-color=\"\" data-darkreader-inline-bgcolor=\"\"><span style=\"color: rgb(227, 148, 220); --darkreader-inline-color: var(--darkreader-text-e394dc, #e18cd9);\" data-darkreader-inline-color=\"\">Log validation complete</span></div>", "testData": null, "expectedResult": null, "testCase": null, "userHasAccessToTestCase": null, "stepParameters": [], "customFieldValues": [], "attachments": [], "reflectRef": null } ] } }, "archived": false, "labels": [], "lastTestResultStatus": { "name": "Pass", "i18nKey": "TEST_RESULT.STATUS.PASS", "color": "#3abb4b" }, "customFieldValues": [ { "id": 1392715537, "customField": { "id": 463594, "projectId": 10040, "type": "SINGLE_CHOICE_SELECT_LIST", "index": 11, "name": "Agile Team", "required": false, "archived": false, "options": [ { "id": 2046204, "index": 29, "name": "WeChat", "archived": false }, { "id": 2046207, "index": 24, "name": "Shop", "archived": false }, { "id": 2046209, "index": 26, "name": "Payments", "archived": false }, { "id": 2046211, "index": 31, "name": "Mobile Apps", "archived": false }, { "id": 2046212, "index": 32, "name": "Web", "archived": false }, { "id": 2046213, "index": 33, "name": "Hub", "archived": false }, { "id": 2046214, "index": 1, "name": "Baby Care", "archived": false }, { "id": 2046219, "index": 0, "name": "Apollo", "archived": false }, { "id": 2046231, "index": 6, "name": "Compensation", "archived": false }, { "id": 2046251, "index": 22, "name": "PaaS Team", "archived": false }, { "id": 2046261, "index": 23, "name": "Paymentrs", "archived": true }, { "id": 2046282, "index": 2, "name": "BPWA", "archived": false }, { "id": 2046283, "index": 3, "name": "Business Intelligence (BI)", "archived": false }, { "id": 2046284, "index": 4, "name": "China", "archived": false }, { "id": 2046285, "index": 5, "name": "China Mobile App", "archived": false }, { "id": 2046286, "index": 7, "name": "Database", "archived": false }, { "id": 2046287, "index": 8, "name": "DBDev", "archived": false }, { "id": 2046288, "index": 9, "name": "DevOps", "archived": false }, { "id": 2046289, "index": 10, "name": "EA", "archived": false }, { "id": 2046290, "index": 11, "name": "ERP Apps", "archived": false }, { "id": 2046291, "index": 12, "name": "Front (HUB UI)", "archived": false }, { "id": 2046292, "index": 13, "name": "GHD", "archived": false }, { "id": 2046293, "index": 14, "name": "InfoSec", "archived": false }, { "id": 2046294, "index": 15, "name": "IT Analyst", "archived": false }, { "id": 2046295, "index": 16, "name": "IT Logistics", "archived": false }, { "id": 2046296, "index": 17, "name": "IT Project Management", "archived": false }, { "id": 2046297, "index": 18, "name": "Legacy", "archived": false }, { "id": 2046298, "index": 19, "name": "Messaging", "archived": false }, { "id": 2046299, "index": 20, "name": "Mobile Apps (1)", "archived": false }, { "id": 2046300, "index": 21, "name": "NetOps", "archived": false }, { "id": 2046301, "index": 25, "name": "RIOT (Report & Identity)", "archived": false }, { "id": 2046302, "index": 27, "name": "SysCorp", "archived": false }, { "id": 2046303, "index": 28, "name": "SysOps", "archived": false }, { "id": 2046304, "index": 30, "name": "TechOps", "archived": false } ] }, "customFieldId": 463594, "intValue": 2046209 }, { "id": 1392715538, "customField": { "id": 463615, "projectId": 10040, "type": "CHECKBOX", "index": 18, "name": "Automated Test", "required": false, "archived": false }, "customFieldId": 463615, "booleanValue": true }, { "id": 1392715539, "customField": { "id": 463596, "projectId": 10040, "type": "SINGLE_CHOICE_SELECT_LIST", "index": 13, "name": "Test Type", "required": false, "archived": false, "options": [ { "id": 2046208, "index": 0, "name": "Manual Test", "archived": false }, { "id": 2046239, "index": 1, "name": "Regression", "archived": false }, { "id": 2046240, "index": 2, "name": "Feature", "archived": false }, { "id": 2046305, "index": 3, "name": "WeChat", "archived": false } ] }, "customFieldId": 463596, "intValue": 2046240 }, { "id": 1392727058, "customField": { "id": 463557, "projectId": 10040, "type": "USER_LIST", "index": 1, "name": "Reviewed By", "required": false, "archived": false }, "customFieldId": 463557, "stringValue": "602406929887580068927c29" } ], "parameters": [] }

Here is the cursor export for a test, this should give all the context.

cursor_smartbear_mcp_sqa_project_test_c.md

[dtfiedler]

+1 - looks like a schema mismatch from the API to the MCP failing validation

schema in anyOf, data/values/166/links must NOT have additional properties, 
data/values/166/links must NOT have additional properties, 
data/values/166/links must NOT have additional properties

[7HemiCuda1]

@dtfiedler is this something we can address on my side? if so can you provide a link to what I should tell the Atlassian manager, so that he can fix that?

[dtfiedler]

@7HemiCuda1 - i pinned the MCP to 0.11.0 for now

// opencode.json
{
  type: "local",
  command: ["npx", "-y", "@smartbear/mcp@0.11.0"],
  environment: {
      "ZEPHYR_API_TOKEN": <YOUR API TOKEN>
  }
}

@adrienave - the issue seems to be with something introduced between 0.11.0 and latest (0.13.5) r.e. zod validation of a response schema from the zephyr API

[adrienave]

@7HemiCuda1 Thanks for providing the data, but it doesn't seem to be coming from public API endpoint called by MCP tool.

Could you please call https://api.zephyrscale.smartbear.com/v2/testcases/SQA-T35013 and send me the response (make sure again that no sensitive data stays inside)?

We are trying hard to investigate the issue, it looks like an issue with the Swagger schema validation (like you both said), but so far we cannot see any mismatch between API schema definition and MCP one.
Creating a Testcase having similar content as you just shared isn't enough to reproduce the issue, I'm suspecting the API endpoint used by MCP to be in some cases returning more data than expected.

[adrienave]

@7HemiCuda1 - i pinned the MCP to 0.11.0 for now

// opencode.json
{
type: "local",
command: ["npx", "-y", "@smartbear/mcp@0.11.0"],
environment: {
"ZEPHYR_API_TOKEN":
}
}

@adrienave - the issue seems to be with something introduced between 0.11.0 and latest (0.13.5) r.e. zod validation of a response schema from the zephyr API

Ok, that's good to know, thanks for helping narrowing it down.

zod schemas for Zephyr have been reworked in 0.10.0 though, but I can see zod itself has been upgraded to a different version in early January. That could be related.

[7HemiCuda1]

@adrienave
here is the response as you requested.
{ "id": 294678793, "key": "SQA-T35013", "name": "Verify Zephyr test step actualResult is empty for passing steps", "project": { "id": 521183, "self": "https://api.zephyrscale.smartbear.com/v2/projects/521183" }, "createdOn": "2026-01-27T22:46:09Z", "objective": "validating the Playwright Zephyr Integration", "precondition": null, "estimatedTime": null, "labels": [], "component": null, "priority": { "id": 9466381, "self": "https://api.zephyrscale.smartbear.com/v2/priorities/9466381" }, "status": { "id": 9466229, "self": "https://api.zephyrscale.smartbear.com/v2/statuses/9466229" }, "folder": { "id": 30444418, "self": "https://api.zephyrscale.smartbear.com/v2/folders/30444418" }, "owner": { "accountId": "602406929887580068927c29", "self": "https://usana.atlassian.net/rest/api/2/user?accountId=602406929887580068927c29" }, "testScript": { "self": "https://api.zephyrscale.smartbear.com/v2/testcases/SQA-T35013/teststeps" }, "customFields": { "Package Information": "", "Dev Team": null, "Reviewed By": "602406929887580068927c29", "Subscription/Cache/Refresh Schedule": "", "Items to Deploy": "", "Issue Key": "", "Markets": null, "Severity": null, "Associate Impact": null, "Agile Team": "Payments", "Downtime Type": null, "Product Team": null, "Acceptance Criterion": "", "Automated Test": true, "Additional linked components": [], "Test Type": "Feature", "Browser": "" }, "links": { "self": "https://api.zephyrscale.smartbear.com/v2/testcases/SQA-T35013/links", "issues": [], "webLinks": [] } }

[7HemiCuda1]

This is the request from the MCP. I updated to the version "command": ["npx", "-y", "@smartbear/mcp@0.11.0"],

Request to the MCP
This is the call from the client (Cursor) to the MCP server that runs the Zephyr integration. In JSON-RPC 2.0 style it looks like:
{
"jsonrpc": "2.0",
"id": "",
"method": "tools/call",
"params": {
"name": "get_test_case",
"arguments": {
"testCaseKey": "SQA-T35013"
}
}
}
{ "jsonrpc": "2.0", "id": "", "method": "tools/call", "params": { "name": "get_test_case", "arguments": { "testCaseKey": "SQA-T35013" } }}
Method: tools/call (or equivalent “invoke tool” method in your MCP setup).
Tool name: get_test_case (exposed in Cursor as something like mcp_smartbear_zephyr_get_test_case).
Arguments: only testCaseKey; value "SQA-T35013".
So: the request to the MCP is “call tool get_test_case with testCaseKey: "SQA-T35013"”.
Response from the MCP
The response from the MCP in your case was an error, because the Zephyr API payload didn’t match the tool’s declared output schema:
{
"jsonrpc": "2.0",
"id": "",
"error": {
"code": -32602,
"message": "Structured content does not match the tool's output schema: data/project must NOT have additional properties, data/project must NOT have additional properties, data/priority must NOT have additional properties, data/priority must NOT have additional properties, data/status must NOT have additional properties, data/status must NOT have additional properties, data/folder must NOT have additional properties, data/folder must NOT have additional properties, data/folder must be null, data/folder must match a schema in anyOf, data/links must NOT have additional properties, data/links must NOT have additional properties, data/links must NOT have additional properties"
}
}
{ "jsonrpc": "2.0", "id": "", "error": { "code": -32602, "message": "Structured content does not match the tool's output schema: data/project must NOT have additional properties, data/project must NOT have additional properties, data/priority must NOT have additional properties, data/priority must NOT have additional properties, data/status must NOT have additional properties, data/status must NOT have additional properties, data/folder must NOT have additional properties, data/folder must NOT have additional properties, data/folder must be null, data/folder must match a schema in anyOf, data/links must NOT have additional properties, data/links must NOT have additional properties, data/links must NOT have additional properties" }}
Code: -32602 (invalid params / invalid result).
Message: The MCP server successfully got a 200 from the Zephyr API, then validated that body against its output schema, and failed because of the extra properties on project, priority, status, folder, and links.

[adrienave]

Thank you for the updated content @7HemiCuda1 , it's very useful for the investigation.

So I have some good news: I have been able to reproduce this issue using Cursor IDE Chat. I don't know why it seems to be impossible to reproduce on Visual Studio Code Copilot Chat.

I'm still not sure what's the root cause of the issue, but now I can investigate it better.
I also tracked down the first version on which the bug appears: it's 0.13.1.
@dtfiedler I advise you then to switch to 0.12.1 version, since it should be working fine, and will provide you more Zephyr tools than 0.11.0 is.

Another alternative for you both could be to switch to Visual Studio Code for the time being, the issue should not be there (unless it's working for me for other reasons).

[adrienave]

Oh also @7HemiCuda1 , if it's still not working for you even on older versions, try restarting your whole IDE and then restart the MCP server. Try cleaning the cache as well.
It could be that it's still using the previous version.