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

readOnlyHint=true already declares the read-only safety profile, and the description adds value by disclosing pagination ("returns a page of people") and that all filters are optional. It does not mention default page size, total counts, or the POST-for-search quirk's implications, so it adds some but not rich behavioral context.

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, front-loaded clauses with no padding; the purpose and pagination hint come first. The trailing REST endpoint note (POST /people/search) is slightly extraneous for an agent but not harmful.

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 13-param, no-required-args search with full schema coverage and no output schema, the description covers the essentials: what it returns (a page), that filters are optional, and the read-only nature. It omits pagination mechanics beyond "a page", but nothing critical for correct invocation 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 all 13 filters, defaults, and the sort enum are already documented in the schema. The description only reaffirms that filters are optional, adding no syntax or interpretation beyond the schema — the correct baseline of 3.

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+resource ("Search/list people (contacts)") and clarifies the domain object so it is distinguishable from sibling searches like copper_search_companies or copper_search_leads. It does not explicitly name an alternative, but the resource noun is unambiguous.

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?

"All filters optional" gives useful context that an empty call lists people, which is a form of usage guidance. However, there is no when-to-use/when-not guidance, no mention of when to prefer copper_get_person for a known id, and no routing to sibling tools.

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