Create API Key

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

Without annotations, the description takes full responsibility for behavioral disclosure. It explicitly states that the token is only shown once upon creation, which is a critical constraint for the agent to know. However, it omits other behaviors like error handling or permission requirements.

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 very concise with two sentences. The first sentence states the purpose clearly, and the second adds a critical behavioral constraint. No unnecessary words or repetition.

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?

Despite the tool having no output schema, the description does not explain the return value format beyond mentioning the token. It lacks details on success/error responses, prerequisites, or what happens on failure, leaving the agent with incomplete information for a creation tool.

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 does not add additional meaning to the parameters beyond what the schema already provides. The parameter descriptions in the schema are sufficient and the tool description focuses on overall behavior.

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 clearly states 'Create a new API key in Resend' using specific verb and resource, distinguishing it from sibling tools like list-api-keys and remove-api-key. The additional detail about the token being shown only once further clarifies the tool's unique behavior.

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 implies when to use the tool by highlighting that the token must be displayed to the user, but does not explicitly state when not to use it or provide alternatives. Usage context is vaguely implied rather than explicitly guided.

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