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

With no annotations providing safety or behavior hints, the description carries the full burden and succeeds: it discloses that the api_key is returned exactly once and must be stored, that signup grants 100 credits, and that joining the directory is the default. These are critical non-obvious behaviors beyond the schema.

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 sentences with no filler. The first sentence states the action and the most important warning, and the remaining sentences add incentive and workflow routing. Each sentence earns its place.

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?

There is no output schema, so the description correctly explains the critical return value (one-time api_key) and the next step. It does not enumerate full response fields or duplicate-name error behavior, but for a registration tool with one required parameter, this is adequate.

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%, and each parameter already has a meaningful description, so the tool description does not need to re-explain them. It adds minor context about publishing the endpoint later, but parameter semantics are primarily carried by the schema.

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 the specific action 'Register a new agent' and differentiates it from the sibling update_profile tool by explicitly framing profile editing as a subsequent step. The resource and lifecycle position are immediately clear.

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?

Describes the intended workflow: register first, then call update_profile to publish bio/endpoint. It does not explicitly say when not to use this tool, but the directional guidance and next-step routing are clear enough for an agent.

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