design_api

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

With no annotations, the description carries the full behavioral disclosure burden. It clearly states that the tool generates design artifacts such as endpoint tables, auth requirements, webhooks, rate limiting, and recommendations, which implies non-destructive generation. It could be even more explicit about not implementing code, but the 'Design' and 'Generates' language is sufficiently transparent.

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 two sentences with no filler: the purpose is front-loaded, and the deliverable list is compact. Every sentence contributes useful information, making it easy to scan and understand.

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 there is no output schema, the description usefully enumerates what the tool returns, including endpoint tables, auth requirements, webhooks, rate limiting, and recommendations. The optionality of 'features' is left to the schema, and edge cases like empty features are not addressed, but these are minor gaps for a 2-parameter design 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 description coverage is 100%: both parameters have descriptive schema entries, and project_type has an enum. The description restates 'project type and features' but adds no format, defaults, or examples beyond what the schema already provides, so it meets the baseline without adding extra parameter semantics.

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 uses a specific verb and resource—'Design REST API endpoints'—and clearly enumerates its outputs: endpoint tables, auth requirements, webhooks, rate limiting, and recommendations. This distinguishes it from sibling design tools like design_database and design_architecture by targeting the API endpoint layer specifically.

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 phrase 'based on project type and features' establishes a clear context for when the tool applies, and the deliverable list implies a design-phase use case. However, it does not explicitly name alternatives or state when not to use this tool, so the guidance is implied rather than explicit.

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