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

Goes well beyond the annotations: it describes the return shape (header/body/buttons as the signer sees it), discloses that sandbox/stage runs are simulated with no real delivery, and warns that returned signing links and verification codes are sensitive and must not be used to sign for someone else. That is meaningful behavioral context the readOnly/idempotent hints do not convey.

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?

Four tight sentences with the core action front-loaded, and each subsequent sentence adds a distinct fact (response shape, sandbox behavior, sensitivity). Dense but no filler; it could be marginally tightened but nothing is wasted.

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 correctly compensates by explaining the rendered return structure and the sandbox caveat. It does not cover ordering or whether results are paginated/limited, a minor gap for a list tool, 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 description coverage is 100% for the two required IDs, so the schema already carries parameter meaning. The description only restates scope ('for an assignment') without adding format or constraint detail, so the baseline of 3 applies.

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 (List) and a narrowly scoped resource (WhatsApp notification messages sent for an assignment), which no sibling tool covers. An agent can tell this apart from resend_notification or list_document_activities without opening the 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?

Names an explicit use case -- troubleshooting WhatsApp delivery for a single assignment -- which tells the agent when this tool is the right call. It stops short of stating when-not to use it or pointing at resend_notification as the alternative for re-sending, so it does not reach a 5.

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