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

With no annotations, the description carries the full behavioral burden. It does disclose two important traits: spending limits ($100/order, $250/day) and that the key is shown only once. However, it omits auth requirements, idempotency behavior, error conditions, and what happens if the agent is already registered.

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?

The description is front-loaded and very compact, with no wasted words. However, for a registration tool with five parameters and no annotations, this brevity is not appropriately sized and leaves critical details unstated.

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?

Given five parameters, 0% schema description coverage, no annotations, and no output schema, the description is far from complete. It covers only key limits and one-time display, while omitting parameter meanings, registration side effects, and authentication context.

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 0% and five parameters (name, model, contact, homepage, operator) have no descriptions in either the schema or the description. The description adds no meaning for any input parameter, leaving an agent to guess what each field expects.

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?

The description says 'Get a self-service API key', which identifies the primary outcome but does not explicitly frame this as registering an agent or clarify how the agent-registration inputs map to that output. It is more specific than a tautology but not fully clear about the tool's purpose relative to its name 'register_agent'.

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?

The description provides no when-to-use guidance, prerequisites, or alternatives. It implies you call it to obtain a self-service API key, but does not say whether this is for first-time registration, whether an existing key should be replaced, or how it relates to sibling tools like whoami.

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