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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, so the safety profile is covered. The description adds a useful sunset date but says nothing about what gets destroyed or whether the cancellation is reversible, and instead spends two of its three sentences on an unrelated 'listing service / no paid placement' disclaimer that has no bearing on cancelling a message.

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?

The deprecation sentence is well front-loaded and earns its place, but the following two sentences about being a 'listing service, not a lawyer referral service' and lawyers not paying for placement are pure boilerplate that does not describe this tool. Two-thirds of the text 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?

For a deprecated alias with an output schema and annotations, the essential forwarding information is present. However, an agent still lacks confirmation of what state change occurs and whether the cancelled message is recoverable, and the off-topic policy sentences dilute rather than complete the picture.

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 only 50%: status_token is documented in the schema, but referral_id has a pattern and no explanation of where it comes from. The description supplies no parameter meaning at all, so it fails to compensate for the undocumented required parameter.

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?

The description identifies the tool only as the 'older name of cancel_contact_request,' which conveys the cancellation domain but never states what is actually being cancelled (a message / contact request) or what the operation does to it. The title 'Cancel my message' carries most of the actual meaning; the description's own wording is a redirect rather than a purpose statement.

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?

It gives an explicit routing instruction ('use cancel_contact_request') plus a concrete deprecation horizon (kept until 2026-12-15), which is exactly what an agent needs to avoid calling a deprecated alias. It stops short of 5 because it never says whether this tool should ever be invoked (e.g., only for legacy clients), leaving a small ambiguity.

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