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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful context beyond that: it warns the results 'Contains personal data' (PII handling) and notes the result set is 'Page-numbered', plus the underlying GET /customers/search endpoint. It does not describe ordering or what happens on no-match.

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 tight clauses, front-loaded with the primary search behavior, then the optional narrowing, then the PII/pagination caveats. No filler sentences and nothing buried.

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 no output schema, the description covers the matching rule, the narrowing filters, pagination existence and the PII sensitivity. The main omission is any statement of result ordering or how the agent should page using next_page, but the schema's page description partially covers that.

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 only 50%: q, page and limit carry descriptions, while tag, state and location_id are bare enums/strings in the schema. The description compensates by explaining that results can be narrowed by location, visit state or tag, and it restates the prefix-match semantics of q. Page/limit behavior is left entirely to the schema, so it adds value but not complete coverage.

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 ('Search customers') plus the exact matching semantics ('prefix match on name, phone, e-mail or customer id'), which distinguishes it from the sibling list_customers that presumably enumerates without a query term. It stops short of explicitly naming list_customers or get_customer as the alternative, so it doesn't fully earn a 5.

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?

The description implies when the tool applies (you have a partial identifier and want a prefix match) but never states when to use it instead of waitwhile_list_customers or waitwhile_get_customer, and gives no exclusions or prerequisites. Usage is inferable rather than stated.

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