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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: the 10-company cap and the warning that not every domain may resolve, advising the caller to compare requested vs enriched counts rather than assume success.

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?

Front-loaded with the core action and cap, then the parameter, then the return caveat, then the sibling pointer. Well ordered and mostly waste-free, though the appended pricing boilerplate inflates length relative to the actionable content.

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?

Despite an output schema existing, the description helpfully calls out the key response fields and, more importantly, the semantic caveat that counts may not all match. Together with the sibling routing and the 10-domain limit, an agent has everything needed to call and interpret 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?

Schema description coverage is 100%, so the schema already documents the domains array, bare-domain format, and www/@ exclusion. The description reinforces the 'array of bare domains' shape but adds no syntax or format detail the schema lacks, so baseline 3 applies.

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?

States a specific verb (enrich) and resource (organizations/companies) with scope (up to 10 in one call). Explicitly distinguishes itself from the sibling get_apollo_organizations_enrich by noting that the single-domain case is a plain GET, so an agent can choose between them without opening either schema.

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?

Provides a clear routing rule: use this for multiple domains (up to 10), use get_apollo_organizations_enrich for one domain. That covers the primary selection decision, though it doesn't state exclusions such as what to do beyond 10 domains or rate-limit behavior.

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