Fix [FromServices]/[FromContext] parameters leaking into MCP tool schemas#13
Merged
carldebilly merged 2 commits intomainfrom Mar 29, 2026
Merged
Fix [FromServices]/[FromContext] parameters leaking into MCP tool schemas#13carldebilly merged 2 commits intomainfrom
carldebilly merged 2 commits intomainfrom
Conversation
The documentation builder did not filter parameters decorated with
[FromServices] or [FromContext], causing them to leak into MCP tool
schemas as user-facing properties. The option schema builder already
excluded them, so the runtime binding was unaffected, but LLM agents
saw spurious parameters (e.g. service types) in the tool definitions.
Add context-binding and schema-exclusion MCP end-to-end tests with
multi-command context fixtures mirroring real-world nested-context
patterns (session → {id} → screenshot/info).
![github-code-quality[bot]](https://avatars.githubusercontent.com/u/9919?s=60&v=4){kind=small}
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| result.IsError.Should().BeFalse("call with optional param should succeed"); | ||
| var text = result.Content.OfType<TextContentBlock>().FirstOrDefault()?.Text; | ||
| text.Should().NotBeNull(); |
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| result.IsError.Should().BeFalse("omitting optional params should not cause a binding failure"); | ||
| var text = result.Content.OfType<TextContentBlock>().FirstOrDefault()?.Text; | ||
| text.Should().NotBeNull(); |
![devin-ai-integration[bot]](https://avatars.githubusercontent.com/in/811515?s=60&v=4){kind=small}
Address code-quality review: use ! after FluentAssertions NotBeNull() so the compiler knows the variable is non-null for subsequent calls.
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Summary
CoreReplApp.Documentation.cs) did not filter[FromServices]or[FromContext]parameters, causing them to appear as user-facing properties in MCP tool JSON schemas. TheOptionSchemaBuilderalready excluded them correctly, so runtime binding was unaffected — but LLM agents saw spurious parameters (e.g. service type names likemanager,viewers) in tool definitions.session → {id} → screenshot/info) with service injection, including a schema assertion that[FromServices]params are excluded.configureServicessupport toMcpTestFixturefor DI-enabled test scenarios.Test plan
When_HandlerHasFromServicesParams_Then_SchemaExcludesThemverifies service params are absent from schemaWhen_ContextToolCallWithOptionalParams_Then_Succeeds/WithoutOptionalParamscover multi-command context dispatch