{"version":"2.1.119","anchor":"mcp-tool-name-validation","canonical_anchor":"mcp-tool-name-validation","heading":"MCP Tool Name Validation","tier":null,"area":null,"scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.119\/e\/mcp-tool-name-validation","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.119","markdown":"### MCP Tool Name Validation\n\n**What**\n\nClaude Code now validates MCP tool names against the emerging MCP naming standard and warns about non-conforming names.\n\n**Details**\n\n- **Hard failures** (tool rejected): empty names, names exceeding 128 characters, names with characters outside `[A-Za-z0-9._-]`\n- **Soft warnings** (tool registered but warning logged): names with spaces, commas, leading\/trailing dashes or dots\n- Warning output references the MCP specification proposal: [SEP: Specify Format for Tool Names](https:\/\/github.com\/modelcontextprotocol\/modelcontextprotocol\/issues\/986)\n- Registration proceeds for soft warnings: \"Tool registration will proceed, but this may cause compatibility issues.\"\n\n**Evidence**\n\nTool name validation (search for `\"Tool name validation warning\"`, `\"Tool name contains invalid characters\"`, `\"Allowed characters are\"`)"}