fix(aws-diagram-mcp-server): use str for diagram_type param for Gemini compatibility#2430
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…for Gemini compatibility The get_diagram_examples tool's diagram_type parameter used a DiagramType(str, Enum) which does not emit "type": "string" in the JSON schema. Gemini requires an explicit "type" field in tool parameter schemas and rejects calls without it. Change the parameter type to str with a default of 'all' so the schema includes "type": "string". Convert to DiagramType internally, falling back to ALL for unrecognized values. Closes #661
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Pull request overview
This pull request fixes a compatibility issue with Gemini backends by changing the get_diagram_examples tool's diagram_type parameter from a DiagramType enum to a plain str type. The Gemini backend requires an explicit "type" field in the JSON schema for tool parameters, which is omitted when using enum types. The change ensures the generated schema includes "type": "string", making the tool callable from Gemini environments.
Changes:
- Modified
diagram_typeparameter fromDiagramTypeenum tostrwith internal conversion to maintain type safety - Updated default value from
DiagramType.ALLto string'all' - Added fallback logic to use
DiagramType.ALLfor unrecognized string values - Added comprehensive test suite covering string input, invalid values, and all valid enum values
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
src/aws-diagram-mcp-server/awslabs/aws_diagram_mcp_server/server.py |
Changed mcp_get_diagram_examples parameter type to str, added string-to-enum conversion with fallback |
src/aws-diagram-mcp-server/tests/test_server.py |
Added TestMcpGetDiagramExamplesStringInput test class with 4 tests covering string inputs and edge cases |
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Address code quality bot warning about iterating over a type by wrapping DiagramType in list() to make the iteration explicit.
dineshSajwan
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Feb 16, 2026
massi-ang
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Feb 19, 2026
…i compatibility (awslabs#2430) * fix(aws-diagram-mcp-server): use str type for diagram_type parameter for Gemini compatibility The get_diagram_examples tool's diagram_type parameter used a DiagramType(str, Enum) which does not emit "type": "string" in the JSON schema. Gemini requires an explicit "type" field in tool parameter schemas and rejects calls without it. Change the parameter type to str with a default of 'all' so the schema includes "type": "string". Convert to DiagramType internally, falling back to ALL for unrecognized values. Closes awslabs#661 * fix: use list() to explicitly iterate DiagramType enum in test Address code quality bot warning about iterating over a type by wrapping DiagramType in list() to make the iteration explicit.
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ibrahimcesar
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Jun 2, 2026
…i compatibility (awslabs#2430) * fix(aws-diagram-mcp-server): use str type for diagram_type parameter for Gemini compatibility The get_diagram_examples tool's diagram_type parameter used a DiagramType(str, Enum) which does not emit "type": "string" in the JSON schema. Gemini requires an explicit "type" field in tool parameter schemas and rejects calls without it. Change the parameter type to str with a default of 'all' so the schema includes "type": "string". Convert to DiagramType internally, falling back to ALL for unrecognized values. Closes awslabs#661 * fix: use list() to explicitly iterate DiagramType enum in test Address code quality bot warning about iterating over a type by wrapping DiagramType in list() to make the iteration explicit.
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Summary
get_diagram_examplestool'sdiagram_typeparameter fromDiagramTypeenum tostrso the generated JSON schema includes"type": "string""type"field in tool parameter schemas and rejects function calls when it's missing (the enum-based schema omits it)DiagramTypeinternally, falling back toALLfor unrecognized valuesTestMcpGetDiagramExamplesStringInputtest class with 4 tests covering plain string input, invalid input fallback, and all valid enum valuesCloses #661
Test plan
ruff checkandruff formatcleanpyrightclean (0 errors)get_diagram_examplestool is now callableBy submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of the project license.