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

Annotations already declare destructiveHint and idempotentHint, yet the description goes well beyond them: it enumerates exactly what is destroyed (every other key including the calling key, capabilities, webhook, pending email changes, recovery codes), what survives (verified email), and the precise retry semantics (same op_key returns the same token without revoking later keys). It also discloses the version-compatibility behavior and the lockout recovery path, which annotations do not cover.

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 main purpose is front-loaded, but the definition runs long for a two-parameter tool and repeats much of the schema's revoke_others text. The closing sentence about older revisions rejecting the operation is somewhat tangential and difficult to parse.

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?

For a destructive identity-key rotation with no output schema, the description covers consequences, retry behavior, storage advice, and lockout recovery, and it references the returned token. The main remaining gap is not pointing the agent at related siblings or describing the response shape beyond the token mention.

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%, so both op_key and revoke_others are already documented in the schema, largely with the same wording the description repeats. The description adds the 'default keeps existing keys' framing but no syntax or format detail beyond the schema, so the 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?

The description states a concrete action and resource: creating a live-identity credential (rotation), optionally revoking the prior keys. It is specific enough to act on, but it does not explicitly distinguish this from siblings like create_credential, revoke_credential, or recover_credential, and the opening framing ('Create a credential') partially conflicts with the tool's rotation name.

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 real when-to-use guidance: default behavior keeps existing keys, revoke_others=true performs a full rotation, and it advises creating and storing an additional key before revoking the old one for a safe handoff. It stops short of naming alternative sibling tools for related tasks.

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