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

Without annotations, the description carries the full behavioral burden and discloses key traits: it returns API credentials, all three required fields must be provided or the call fails, cold starts can cause the first request to time out with a retry recommendation, and no API key is required. It does not cover rate limits or whether account creation is reversible, which prevents a 5.

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 four sentences, each earning its place: it states the action, lists required fields with explanations, warns about cold-start retries, and clarifies that no API key is needed. It is front-loaded with the most critical information.

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 this is a creation tool with no annotations and no output schema, the description provides sufficient context: required fields, behavior of the return (API credentials), a retry strategy for cold starts, and authentication requirements. It could mention the existence of optional parameters, but overall it is complete enough for an agent to invoke correctly.

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 the baseline is 3. The description adds meaning by specifying the roles of the three required parameters (account owner's email, full name, and team/company name) and emphasizes that all three must be provided or the call will fail. It does not mention the two optional parameters, but the schema already covers them.

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 opens with a specific verb and resource: 'Creates a new Code Registry account and returns API credentials.' This distinguishes it from siblings like get_account, delete_account, and rotate_api_key, which all operate on the same resource but with different actions.

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 clearly implies when to use this tool: to create a new account. It does not name alternatives, but the action is self-contained and does not compete with sibling tools for the same purpose. There is no explicit 'when-not-to-use' guidance, keeping this from a 5.

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