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

Annotations already indicate read-only, idempotent, and non-destructive behavior, so the description adds value beyond those: it discloses the curated source (168 verified definitions), the return components (definition, subject section, citable anchor URL), and the authoritative basis. No behavior is hidden or contradicted.

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 concise sentences front-load the action and resource, then add the return payload and one illustrative list of example terms. There is no filler or redundant repetition of the name, and all text 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?

For a single-parameter read-only lookup tool with an output schema, this description is fully sufficient. It tells the agent what will be returned, why the source is trustworthy, and which kinds of inputs to use, while the output schema covers return-value details.

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 only parameter, 'term', has a complete schema description, so the schema already carries the parameter semantics. The description reinforces it with examples but does not add new meaning about formatting, capitalization, or supported values.

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 a specific action ('look up') on a specific resource ('gemmological term in The Gem Lexicon of Ministry of Gems'), and names example terms that ground what it accepts. It distinguishes itself from siblings such as list_gem_terms and search_gem_knowledge by focusing on defined-term lookup with verification and citation details.

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 gives explicit usage context with examples ('Use for terms such as...'), which helps an agent choose it for dictionary-style lookups. It does not explicitly mention when not to use it or name the alternative sibling tools, but the intended scenario is reasonably clear.

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