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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description adds real value beyond that with the PII warning ('Contains personal data') and the explicit 'cannot send' constraint. It omits pagination mechanics and rate/auth context, so not a 5.

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 plus the endpoint, fully front-loaded: resource and scope first, then filters, then the read-only/PII caveat. Every clause carries information and nothing is padded.

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?

With no output schema, the description usefully enumerates return fields and the state values, and it covers the read-only behavior. For a 10-parameter listing tool it could still note pagination behavior and the external_customer_id filter, so it is strong but not fully complete.

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%, so the description must compensate, and it does by naming the filterable dimensions (location, visit, customer, state, date) that map to location_id, visit_id, customer_id, state, from_date/to_date, and by listing the state enum values in prose. It leaves external_customer_id, desc, limit and start_after solely to 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 precise verb+resource ('List the SMS/e-mail messages Waitwhile sent to and received from customers') and enumerates the returned fields (channel, recipient, body, delivery state, error), plus the underlying endpoint GET /messages. It does not explicitly name the sibling it differs from, so it falls just short of 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?

'This only reads; it cannot send' usefully bounds usage, and the filter list implies when to reach for it, but there is no explicit when-to-use vs waitwhile_get_message or waitwhile_list_visits guidance. Usage is implied rather than stated.

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