aps_capability_issue_challenge

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

No annotations are provided, so the description carries the full burden. It only explains that the tool signs an action and returns a challenge, but omits side effects, idempotency, required permissions, or what happens to the challenge after creation. The mention of 'v0.1' and 'M1' adds little behavioral context.

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 concise (two sentences plus keywords) but front-loads version information ('v0.1') before the core purpose. While short, it could be restructured to highlight the primary action and resource first. Still, it avoids unnecessary fluff.

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 tool has 7 parameters, nested objects, and no output schema, yet the description is minimal. It mentions return values (SinkChallenge, challenge_hash) but does not explain what these are or how they relate to the broader capability token workflow. More context about preconditions, validation, or expected usage is needed for an AI agent to use 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?

The description does not describe any parameters. Schema coverage is approximately 71% (two parameters lack descriptions: validity_seconds, required_policy_freshness). The description could have compensated by explaining these key parameters but did not. It adds no meaning beyond what the schema already provides.

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 clearly states the tool issues a signed canonical action statement and returns a SinkChallenge and its hash. The verb 'issue' and resource 'capability-token sink challenge' are specific. However, it does not explicitly differentiate from siblings like aps_capability_evaluate_authority or aps_capability_sign_effect, though the mention of 'M1' and 'sink challenge' provides some distinction.

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 says the tool is used to bind gateway policy evaluation to a specific action, but it does not state when to use this tool versus alternatives, nor does it provide when-not-to-use guidance. With many similar 'aps_capability_*' sibling tools, explicit usage criteria are missing.

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