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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description still adds useful substance by contrasting the payload with enrichment ('everything enrichment returns plus the deeper fields') and by disclosing usage-based billing. It stops short of rate limits or quota behavior, but that is a minor gap against the annotation coverage.

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 substantive content is two tight sentences with the id-first constraint front-loaded before the supporting detail. Only the auto-injected pricing block bulks it out, so the prose itself 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?

With an output schema present, the return shape need not be re-explained, and annotations carry the safety profile. What remains — how to get the id, what extra fields to expect, and that domains are unsupported — is all supplied, so nothing needed for a correct call 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 coverage is 100% and the single parameter is documented with an example, so the baseline is 3. The description goes further by clarifying the identifier's origin and warning that a domain will not work, which materially reduces the chance of a wrong-value call.

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 and resource — the complete Apollo record for one company — and immediately scopes it to being looked up by Apollo organization id rather than domain. That scoping distinguishes it cleanly from the enrichment and search siblings, so an agent can route without opening a 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?

Explicitly tells the agent how to obtain the required id (via get_apollo_organizations_enrich or post_apollo_mixed_companies_search) and states the exclusion plainly: 'this endpoint cannot take a domain.' Both the positive path and the anti-pattern are covered.

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