register

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds context about the free tier and its limitations, which is useful. However, it does not cover other behavioral aspects such as authentication requirements, rate limits beyond the daily retrieval count, or what happens upon registration (e.g., confirmation process, key delivery method).

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 a single, efficient sentence that front-loads the core action ('Register for an API key') and adds essential context ('Free tier: 10 skill retrievals per day') without any wasted words. Every part of the sentence contributes meaning, making it highly concise and well-structured.

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 the tool's low complexity (0 parameters, no annotations, but with an output schema), the description is reasonably complete. It explains the purpose and key limitation, and since an output schema exists, it need not detail return values. However, it could be more comprehensive by addressing potential prerequisites or post-registration steps, slightly reducing completeness.

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?

The input schema has 0 parameters with 100% coverage, meaning no parameters are documented in the schema. The description does not add parameter details, which is appropriate here since there are no parameters to explain. This earns a baseline score of 4, as it avoids redundancy and fits the tool's simplicity.

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 the action ('Register for an API key') and specifies the resource ('API key'), making the purpose explicit. However, it does not differentiate this tool from potential siblings like 'buy_credits' or 'check_usage', which might involve similar account-related actions, so it falls short of a perfect score.

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 usage context by mentioning the free tier limit ('10 skill retrievals per day'), suggesting this is for initial setup or free access. However, it lacks explicit guidance on when to use this tool versus alternatives like 'buy_credits' for paid plans or 'check_usage' for monitoring, leaving some ambiguity.

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