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

Annotations already cover the safety profile (destructiveHint=true, idempotentHint=true, readOnlyHint=false), so the bar is lower. The description still adds real behavioral context beyond them: coupon release side effects and the fact that paid orders fail and must go to support.

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 sentences, no waste, with the eligibility constraint front-loaded before the paid-order exception.

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?

Eligibility and side effects are covered and annotations handle safety, but for a destructive mutation with four undocumented required parameters and no output schema, the description leaves concurrency semantics and parameter meaning unexplained.

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 0% across four required parameters, so the description carries the full burden, yet it explains none of them. request_capability and expected_revision in particular are opaque – an agent gets no hint that expected_revision is a concurrency guard or what a capability token is.

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 (cancel) and resource (request) plus a scoping condition: only unpaid requests where payment has not started. It does not name the closest sibling, cancel_collection, so an agent can't distinguish those two purely from the description.

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?

The description gives a clear positive condition (unpaid, payment not started) and an explicit exclusion (paid orders require support), which is real when-to-use guidance. It stops short of naming cancel_collection as the alternative for collection-level cancellation.

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