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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so safety is covered. The description adds real behavioral context beyond that: it explicitly promises no challenge or secret is returned, discloses inclusion of the attestation-chain head and a well-known verification URL, and names manager_handle as a side return.

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?

Front-loaded with the core purpose, but bloated by internal ticket references (CO 314, CO 324), an external URL, an embedded return-shape listing, and the near-duplicated 'Never returns any challenge or secret' sentence. Several sentences could be trimmed without loss.

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?

With no output schema, the description carries the return-value burden and does so well, naming the exact fields plus the attestation-chain head and manager_handle. Minor gaps remain about chain-head format and error behavior, but it is sufficient to call the tool 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 100% and the single optional manager_id is already documented as 'The root to read; defaults to the caller.' The description's 'Omit manager_id to read your own' largely restates that schema default, so baseline 3 applies.

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 (Read) and resource (a manager root's bound public key) and enumerates the returned facts (public_key, alg, kid, bound_at). It does not explicitly distinguish itself from the many sibling federation_* tools, but the purpose is unambiguous.

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?

Offers one piece of usage guidance: 'Omit manager_id to read your own.' It does not state when to use this versus alternatives, nor any exclusions or prerequisites, leaving usage mostly implied.

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