Rebuild Local FTS Index

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

The description explains the destructive (clear and rebuild) and safe (returns count) behaviors beyond annotations. Despite the destructiveHint=false annotation, the description aligns with idempotentHint=true, indicating index rebuilding is not destructive to user data.

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 concise with two sentences, front-loading the action and purpose. Every word is informative without redundancy.

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?

For a zero-parameter tool with output schema, the description covers all needed context: what it does, when to use, and what it returns. No gaps remain.

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?

The tool has no parameters, so schema coverage is 100%. The description adds no parameter info, but this is acceptable per the baseline of 4 for zero parameters.

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 tool clears and rebuilds the local FTS5 index from cached messages, specifically INBOX and Sent. It distinguishes from sibling tools like fts_search and fts_status by its rebulid action and use case.

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 specifies intended use after major mailbox changes or when fts_search returns stale results, providing clear context. However, it does not explicitly state when not to use or mention alternatives.

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