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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds genuinely new behavioral facts: a 50-match cap and the absence of pagination. It stops short of describing match semantics (exact vs. partial/fuzzy) or result ordering, which would matter for search behavior.

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 sentences: capability, when to use, and the pagination limitation plus escape hatch. Front-loaded with the operation and free of filler.

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 one-parameter read-only search with an annotated safety profile, this is nearly complete — the match cap and pagination stance are disclosed even without an output schema. The only real omission is whether matching is exact or partial and how results are ordered.

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 `q` is fully documented in the schema, so the baseline is 3. The description's 'by email, name, or external ID' restates the schema's match targets without adding syntax, exactness, or formatting guidance.

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 (search) + resource (contacts) + matching fields (email, name, external ID), and explicitly sets itself apart from meisa_list_contacts. An agent can distinguish it from the list sibling 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?

Gives explicit when-to-use triggers ('user mentions a specific person by name or email', 'do I have a contact for X?') and names the alternative for the opposite case ('for browsing large lists use meisa_list_contacts'). Nothing is left to inference.

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