mcp_index_scan

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description must carry full burden. It discloses token savings (66%) but fails to mention side effects like whether the index is overwritten or appended, or any permissions needed. This is insufficient for a tool performing a potentially expensive operation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single efficient sentence that front-loads the action and includes a key benefit (token savings). It wastes no words, though it could benefit from brief parameter explanations.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the presence of an output schema (not shown) and two undocumented parameters, the description lacks completeness. It doesn't explain output structure, parameter behavior, or usage context beyond the default. A more thorough description is needed for a scan tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, and the description does not explain any parameters (triggered_by, config_filter). The schema alone provides default values but no semantic context, so the agent gets no added value from the description.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('Scan all MCP servers and index their tools') and distinguishes from siblings like mcp_index_rebuild by noting the default behavior (configured servers only). This provides a specific verb and resource scope.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies when to use (scanning with config_filter default) but does not explicitly state alternatives or when not to use. There is no guidance on trade-offs versus mcp_index_rebuild or other scanning tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.