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fix(mcp): with_prefix names the tool <prefix>__<tool> - #323
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McpToolAdapter::with_prefix / from_client_with_prefix stored the prefix but name() and label() returned the server's raw tool name, so two MCP servers offering the same tool (or a server tool named like a built-in) gave the agent duplicate tool names, which a provider rejects. The name is now computed once at construction, as the OpenAPI adapter's with_name_prefix does (`prefix__tool`); execute still calls the server with its own name. Test: two servers both offering `search`, called through the prefixed name; it fails without the fix. Reported by the yobuild session (found in yologdev/yobuild#11's review). Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01T7iq5hpndSiHQcnAsywKuG
…ests - Docs: the MCP guide shows how to prefix a server's tools (the with_mcp_server_* helpers add none) and that with_tools replaces the list; tools.md notes the agent's own tools are not de-duplicated; the pointer is OpenApiConfig::with_name_prefix (not the adapter); provider name limits are hedged and the prefix is not validated. - Tests: the client's call timeout is carried onto prefixed adapters (fails without it); a second prefix replaces the first; the other server gets no tools/call; tests/mcp_prefix_agent_test.rs runs two prefixed servers through an Agent: the model's `web__search` reaches only the web server, as `search`, and ToolExecutionStart names `web__search`. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01T7iq5hpndSiHQcnAsywKuG
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Bug
McpToolAdapter::with_prefixandfrom_client_with_prefixstored the prefix, butname()andlabel()returned the server's raw tool name, and nothing else read the prefix. Two MCP servers offering the same tool, or a server tool named like a built-in (bash,read_file), therefore still gave the agent duplicate tool names. yoagent doesn't de-duplicatewith_tools, so a real provider rejects the request. A caller using the prefix to avoid this was silently unprotected.Reported by the yobuild session, from the review of yologdev/yobuild#11. yobuild now uses
from_clientand refuses duplicate names itself, so it does not depend on this fix.Fix
<prefix>__<tool>with a prefix. This is the same form as the OpenAPI adapter'swith_name_prefixand what the field's doc comment already described.name()andlabel()return it.executestill calls the server with its own tool name._and-, and 64 characters on most providers.Tests
searchbecomedocs__searchandweb__search. A call throughweb__searchreaches that server astools/callwithname: "search", and an unprefixed adapter keepssearch. The test fails with the fix reverted.cargo test --all-features, clippy-D warningswith all features and on wasm32 (decision), rustdoc, fmt.CHANGELOG: Unreleased.
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