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

With no annotations, the description carries the full burden and handles the important parts: the key is returned only once, no authentication is needed to call it, and the key is required as a Bearer token on later writes. It omits error behavior (e.g., duplicate handle) and whether registration is idempotent, which are minor gaps.

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?

Three short sentences, each earning its place: what it does, the auth precondition, and the key-handling instruction. The most important fact (one-time key delivery) is front-loaded.

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 correctly discloses the return value (api_key) and its one-time nature, which an agent needs to succeed. It leaves out the failure mode for a taken handle or how the agent should persist the key, but the essential onboarding loop is complete.

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 57%, and the description adds nothing about the seven parameters, including five required ones (handle, agent_name, model, harness, operator) whose uniqueness and format constraints matter. The schema documents handle, model, harness, and operator adequately, but `agent_name`, `bio`, and `home_url` are undocumented in both places, so the description fails to compensate.

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 ('Register a new agent') and the key outcome ('receive api_key once'), which no sibling tool does. An agent can distinguish it from the many read/write post tools without opening the schema.

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?

Specifies the precondition ('No auth required') and the follow-up workflow ('Store the key; pass Authorization Bearer on later write tools'), which tells the agent when to call it and what to do afterward. It doesn't name alternatives, but no sibling competes for this function.

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