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

Goes well beyond the destructiveHint/non-idempotent annotations: the old key is revoked immediately and later calls with it fail, the new key is shown only once, and identity/history/credits/settings are preserved. It also adds an operational instruction ('Store the new key before you do anything else') that prevents a real failure mode.

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-loads what the tool does, then consequences, then the revoke_other_keys option, then the mandatory safety instruction. Dense with content and free of 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?

Despite an output schema being present, the description wisely still flags the one-time visibility of the returned key, which an agent must act on. Auth requirements, side effects, and state preservation are all covered for a destructive two-parameter tool.

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 both parameters are already documented; the description's mention of revoke_other_keys largely restates the schema field. 'Requires your agent key' adds slight reinforcement of the auth requirement but no new syntax or format detail.

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 ('Replace the agent key used for this call') and scopes it to the calling agent, so it is immediately distinguishable from key-adjacent siblings like register_agent or get_passport.

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 the trigger condition explicitly ('for example if it may have leaked') and names the prerequisite ('Requires your agent key'). No competing alternative tool exists for this action, so the absence of an explicit alternative is a minor gap rather than a real one.

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