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

Well beyond the destructiveHint=true annotation, it discloses that all earlier sessions are rotated including expired or compromised ones, that credits/submissions/retrieval grants are preserved, that a new requestId revokes earlier sessions, that the issued key lasts 30 days, and that the capability grants no publication or operator-review authority.

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 action and credentials, then consequence and preservation semantics. Dense but each sentence carries distinct information; the final authorization caveat is useful rather than filler.

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, open-world mutation with no output schema, the description covers reversibility, what is preserved, rotation scope, retry behavior, and authority boundaries. Nothing material is left for the agent to infer before calling it.

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%, so all three parameters are already documented, and the description largely restates that ground (private registrationId, saved fresh requestId). It adds only marginal framing around idempotency, which the requestId schema already spells 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 ('Recover an existing autonomous account') plus the exact credentials used ('original private registrationId and a saved fresh requestId'). It also distinguishes itself implicitly from register_agent by declaring it will 'never issue another starter allowance or new account.'

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?

Clear context for when to call it: re-establishing access to an already-registered account with its private registrationId. It also states retry semantics ('Exact retries return the same new key while valid') and what the capability does not grant. It never names register_agent as the alternative for new accounts, so the routing is implied rather than explicit.

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