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

Annotations already carry readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable non-obvious behavior: credit consumption per record rather than per call, and the instruction to read `missing_records` because not every input may match. It does not contradict 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?

Four tight sentences, each earning its place: purpose, request shape, response caveat, credit economics, and sibling comparison. The most important facts are front-loaded and there is no filler.

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 tool with 6 params (1 required), full schema coverage, an output schema, and annotations covering safety, the description adds the remaining decision-relevant context: batch size, credit costing, partial-match handling, and when to prefer this over the single-match sibling. Nothing an agent needs to call it correctly is missing.

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 100%, so the schema fully documents all six parameters. The description adds light clarity by explaining that `details` accepts the same identifier objects as `post_apollo_people_match`, and it ties credit cost to enriched records rather than the call itself. This is helpful but not transformative, so a 3 at baseline 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 opens with 'Enrich up to 10 people in one call' – a specific verb, resource, and scope. It explicitly differentiates from the single-person sibling post_apollo_people_match by noting the same identifier objects and pointing to the simpler single call for one person, so an agent can distinguish tools without opening schemas.

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?

It gives a clear decision rule: 'Use this over a loop of single calls: same credits, one round trip,' and explicitly states the boundary case, 'For a single person post_apollo_people_match is simpler.' This is direct when-to-use versus alternative guidance with no ambiguity.

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