search_equities

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds that it reads entirely from a local cache (no API call) and returns an empty list if the cache is never populated. This adds valuable behavioral context beyond the annotations.

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 well-structured with clear sections (purpose, usage, behavior, plans, source, args). It is relatively concise, though the cache mention appears twice (once in the behavior paragraph and again in the source line). A slight redundancy but not detrimental.

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 single parameter and the presence of an output schema (so return format doesn't need description), the tool description covers the key aspects: purpose, usage, behavior, parameter semantics, and edge case (empty cache). It is complete enough for an agent to decide on and invoke the 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?

The input schema only defines 'name' as a required string with no description (0% coverage). The description fully compensates by explaining that it accepts partial or full company names, is case-insensitive, matches anywhere in the name, and supports both Japanese and English names. This is essential for proper usage.

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 it searches for listed stocks by company name (reverse lookup from name to code). It specifies the resource ('equities_master cache') and the action ('search'). It distinguishes itself from siblings as the only tool performing a name-to-code lookup.

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?

Explicitly says 'Use when the user knows a company name but not the stock code' and provides example queries. It does not explicitly state when not to use or compare with alternatives, but the sibling list contains no other search tool, so the guidance is sufficient.

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