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

Annotations only declare readOnlyHint=false and destructiveHint=false; the description goes well beyond that by explaining the key-custody model (Tango signs vs. self-held Ed25519 key) and the multi-step registration workflow that the 'attested' mode triggers. It stops short of describing failure modes, permission requirements, or the returned identity payload, so it is strong but not exhaustive.

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 the purpose, then layers key-mode guidance, scoping, prerequisite, and a reference link in a logical order. It is a bit dense with run-on clauses, but nearly every sentence carries actionable content for a 9-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 9 parameters (only 1 required), high schema coverage, and no output schema, the description supplies the workflow context the schema cannot (prerequisite whoami, post-creation follow-ups). It omits any mention of reuse/roles/harness defaults and expected return, but those are handled adequately by the schema.

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 89%, so the schema already carries most parameter meaning. The description still adds real value by explaining when to choose each key_mode value and that clients scoping is optional, supplementing the enum's terse 'delegated (default)' / 'attested' definitions.

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 (provision) and resource (worker / agent identity) and frames the outcome ('so you can claim, lease, and hand off tasks'). This clearly separates it from sibling mutations like update_worker, archive_worker, and delete_worker without needing their schemas.

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 explicit when-to-use guidance for both key modes ('delegated' in an ephemeral sandbox vs 'attested' when the key is durable), names the required follow-up tools (request_key_challenge, register_worker_key), and tells the agent to call whoami first. Alternatives and conditions are all spelled out.

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