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

The readOnlyHint=false annotation already signals this is a mutating operation, so the description's job is lighter. It adds the meaningful constraint that only unformed requests are cancellable, but says nothing about irreversibility, required permissions, or what happens on failure for an already-formed request.

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?

A single short sentence with no wasted words, and the key constraint is front-loaded. It is efficient, though its brevity borders on under-specification rather than optimal conciseness.

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 mutating tool with no output schema and an undocumented required parameter, the description is too thin. It omits the identity of request_id, error behavior, and any confirmation of what cancellation entails, leaving real gaps for an agent to call it correctly.

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%: api_key is documented in the schema, but request_id has no description anywhere. The description does not explain what request_id refers to or where to obtain it, so it fails to compensate for the coverage gap.

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 states a specific verb (取消/cancel) and resource (委託/request), and adds a scope qualifier (尚未成立, not yet formed) that narrows which requests qualify. It does not distinguish this tool from siblings such as create_request, list_requests, or deal_action, so it stops short of a 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?

The phrase 尚未成立 implies a precondition for use — only requests that have not yet been finalized can be cancelled — which is useful implied guidance. However, it names no alternative tool and gives no explicit when-not guidance (e.g., what to do for an already-formed request).

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