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

Annotations already declare the tool read-only, idempotent, and non-destructive, so the description's behavioral additions of case-insensitive ranking, field weighting, and the exact return shape (term, category, definition snippet) add meaningful context beyond annotations. No contradiction exists between the description and 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?

Three sentences deliver scope, ranking details, return format, and an alternative tool pointer without any filler. The most critical information is front-loaded, and each sentence contributes distinct value.

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?

Even without an output schema, the description explains what is returned (term, category, definition snippet) and how matches are ranked. The limit parameter is documented in the schema, and annotations cover safety attributes, so nothing essential is missing for an agent to invoke this tool 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 schema description coverage at 100%, the schema already fully documents both 'query' and 'limit'. The description adds contextual nuance about ranking behavior and case-insensitivity, but it does not add new parameter-level meaning beyond what the schema provides.

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 uses a specific verb ('search') and a defined resource ('the 90 entry diamond and gemology encyclopedia'), clearly distinguishing it from sibling tools. It also explicitly names the sibling 'define' as the alternative for fetching full entries, making the scope unambiguous.

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 includes an explicit alternative instruction: 'Use define to fetch a full entry,' which guides the agent toward the correct sibling when a full entry is needed rather than a snippet. It does not explicitly contrast with search_inventory, but the encyclopedia scope and title make the differentiation clear enough.

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