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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds meaningful behavioral context beyond the annotations: the result is 'compact' candidates, there is a $0.05 cost, and an API key is required. These details help an agent anticipate side effects and requirements.

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 a compact two-sentence definition with no filler. The primary action and scope are front-loaded, and the routing hint, cost, and auth requirement are each given in clearly minimal phrasing.

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?

With an output schema present, return-value documentation is covered, and annotations cover the safety profile. The description adds cost, auth, and a sibling preference. The only completeness gap is the undefined limit parameter, but overall the agent has enough context to invoke the 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?

Schema description coverage is 0%, so the description must compensate. It explains that person_id is a direct lookup key and that query can include alias/name/payment signals, giving meaning to two of the three parameters. The limit parameter is left unexplained, which is the only gap.

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 operation: finding compact identity resolution candidates by person_id or query, and enumerates the query signals (alias/name/payment signals). It explicitly distinguishes itself from the bulk get_people sibling, which is exactly the kind of differentiation an agent needs.

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 direct routing guidance: 'Prefer over bulk get_people.' It also identifies the two input modes (person_id or query), making the intended use context reasonably clear. It does not exhaustively contrast with related search/resolve tools, but the explicit sibling preference is strong guidance.

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