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

With no annotations, the description carries the full behavioral burden and does so well: it explains the narrowing invariant at every delegation hop, requires a human at the root, reports whether the grant is signed, and states that the answer is the mandate on file as of checked_at rather than proof of current permission. These are substantive behavioral traits 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 front-loaded with the core purpose and key invariant, and most sentences earn their place by adding trust-model semantics. It is slightly verbose in places, such as the emphasis that credential validity and mandate compliance 'are different questions,' but the length is largely justified for a complex authority-resolution tool.

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?

Given one required parameter, no annotations, and no output schema, the description supplies the missing context an agent needs: what is resolved, how delegation chains work, what invariant is enforced, what the timestamp means, and the limitation that the result is recorded evidence rather than live proof. Nothing critical is absent for correct invocation and interpretation.

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 100%, and the schema already explains that query accepts an agent name, credential id, or agent UUID. The description does not add format or syntax guidance for the query parameter, so baseline 3 is appropriate.

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 and resource: resolving the human mandate behind an AI agent, including actions permitted, value cap, expiry, signature status, and delegated chain. It also clarifies the key distinction from a sibling-like concern by noting that a valid credential may still be acting outside its mandate, which helps an agent separate this from verify_agent.

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 usage condition: 'Use this before letting an agent transact, sign, spend or commit on someone else's behalf.' It also warns about timing by saying to check again at the point of action, which is concrete when-to-use guidance rather than implied context.

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