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

Annotations already declare this a read-only, idempotent, closed-world operation; the description adds genuinely new behavior: no lookup credit is consumed and name-only matches are reported as possible matches, not confirmations. That match-confidence rule is the key behavioral fact an agent needs and it is not in the annotations.

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?

Two tight sentences with no filler; the core check is front-loaded, then the credit-cost and match-confidence caveat follow. Every clause carries information.

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?

An output schema exists, so return-value explanation is unnecessary, and the description covers inputs, cost, and match-confidence semantics. Minor gap: it doesn't state what a no-match result implies (e.g., safe to add via add_person_to_crm) or whether e-mail matching is exact.

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%, including the 'required unless an e-mail is given' rule and the profile_url guidance, so the schema already carries the semantics. The description only restates the name-or-e-mail key and optional profile link, adding no format or precedence detail beyond the schema.

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 (check/find) and resource (a person in the customer's connected CRM) plus the lookup keys used. It names confirm_possible_match as a follow-up but does not distinguish itself from other lookup siblings such as search_crm, find_contact_details, or find_company_details.

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 clear operating context: uses no lookup credit, can be keyed by name or e-mail, and a name-only hit must be treated as a possible match rather than proof. It also routes the agent to confirm_possible_match for the customer's answer. It stops short of explicitly saying when to prefer this tool over search_crm or find_contact_details.

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