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

Annotations already establish readOnly/idempotent/non-destructive, and the description adds genuinely new behavioral facts: no challenge or secret is ever returned, the attestation chain head is included, and the full chain lives at /.well-known/key-attestation-chain. The duplicated 'never a challenge or secret' sentence weakens but does not negate the value added.

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 correctly with the purpose, but redundancy is real: 'Never a challenge or secret' appears twice, and the returns list is restated in two different sentences. The example call with empty arguments adds near-zero information for a zero-required-parameter 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?

With no output schema, the description carries the burden of describing returns and does so, including the extra manager_handle field whose format is explained. It omits what happens for an unknown or unreachable manager_id, which is the main remaining gap for a cross-tenant read.

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 parameter is already documented. The description goes beyond the schema by explaining the default semantics of omitting manager_id ('read your own'), which is the one behavioral detail the schema does not spell out.

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 and resource — 'Read a manager root's bound public key' — and immediately names the concrete fields returned (public_key, alg, kid, bound_at). The counterparty-verification framing distinguishes it from siblings like federation_attest or federation_solvency.

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?

Gives clear situational context ('A counterparty verifies this root's signatures against it') and an explicit default behavior ('Omit manager_id to read your own'). It does not name an alternative tool or state when another sibling such as federation_attest is the better call, so it stops short of full routing guidance.

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