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

With no annotations, the description carries the behavioral burden. It discloses that only the issuing caller can revoke, the cancellation requires a signed term-delegation-cancel-v0 statement, a delegated credential cannot authorize cancellation, and delegation is single-hop. This is meaningful safety-relevant context beyond the schema.

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 description is compact and front-loaded with the primary action. Every sentence adds useful context about the delegation model or the cancellation route, though the second sentence is dense and could be parsed more easily.

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?

The description covers the purpose, authorization, and signing behavior well, and it warns against common misuse involving delegated credentials. However, it omits parameter-level semantics, success/failure behavior, and any consequences of cancellation, which is noticeable since there is no output schema to fill those gaps.

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 25%, and the description does not explain subject_id, delegate_public_key, or created. It adds some context around the signature and signing key, but the meaning of three out of four required parameters is left to inference from their names and patterns.

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 opens with a specific verb and resource: 'Revoke one delegation grant the caller (the issuer) issued.' It clearly scopes the action to the caller's own grants and distinguishes itself by noting it mirrors the REST cancellation route, so it is not confused with related tools like revoke_credential.

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 implies when to use the tool: when the issuer wants to cancel a delegation grant. It adds contextual boundaries such as 'a delegate can grant nothing' and REST-only issuance, but it does not explicitly name alternatives or state when not to use this tool versus a sibling.

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