lean_local_search

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

Annotations already indicate readOnlyHint=true and idempotentHint=true, so the agent knows it's safe. The description adds 'Fast local search,' conveying performance characteristics, and clarifies the tool's purpose (verifying existence), which complements the annotations without contradiction.

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?

Two sentences with no wasted words. The first sentence conveys purpose and key characteristic (fast). The second provides a usage hint. Every sentence is substantive and earns its place.

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 simple nature of the tool (declaration search), the description fully covers what it does and when to use it. Annotations cover safety, and the existence of an output schema means return values need not be described. The description is complete for an agent to decide and invoke correctly.

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?

With 100% schema description coverage, the schema already documents each parameter adequately. The description adds overall context that the query is a declaration name or prefix, but no parameter-specific details beyond what the schema provides. Thus a baseline score of 3 is appropriate.

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 'Fast local search to verify declarations exist.' This is a specific verb (search/verify) and resource (declarations). It distinguishes from sibling tools like lean_leansearch (global search) and lean_loogle (broader search) by emphasizing local and verification-focused purpose.

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 instruction 'Use BEFORE trying a lemma name' provides explicit context for when to invoke this tool. While it doesn't list alternatives or specify when not to use, the guidance is clear and actionable, differentiating it from other search tools.

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