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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds only the REST endpoint and the email/phone incompatibility rule, which the schema already states per-field; it does not say whether matching is exact, prefix, or fuzzy, or whether an empty result is an error.

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 short sentences with the searchable fields front-loaded, followed by the minimum-criterion rule and the mutual exclusion. No filler and nothing redundant with the title.

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 read-only search with full schema coverage and annotations, most needs are met by structured fields. The key missing piece is match semantics (exact vs partial vs case sensitivity) and result ordering/paging behavior, which materially affect how the agent should query and whether it must retry with a different input.

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%, so baseline is 3, but the description adds a constraint the schema cannot express: zero parameters are required yet at least one search criterion must be supplied. That directly affects whether the agent can call the tool legally. It still says nothing about the includes or pagination parameters beyond what the schema documents.

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 (Find) and resource (people) plus the four searchable fields and the endpoint, so the agent knows this is a targeted lookup rather than a listing. It doesn't explicitly contrast with siblings like list_people, search_all, or get_person, so differentiation is inferred from the name rather than stated.

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?

"Give at least one criterion" and "email and phone cannot be combined" give usable invocation constraints. However, there is no guidance on when to choose this over list_people, search_all, or search_companies, and no mention of what to do when a search returns nothing.

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