Check if a URL is allowed by robots.txt

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

With no annotations, the description carries full burden. It discloses that robots.txt is fetched and parsed, the check is for the wildcard user-agent, return values are the verdict and matching rule, and robots.txt is cached for 24 hours. This provides useful behavioral nuance beyond a simple API call.

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?

Three sentences, each earning its place: action, return value, caching behavior. No redundancy or fluff. Information is front-loaded with the core purpose in the first sentence.

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?

For a simple one-parameter tool with no output schema, the description adequately covers purpose, behavior, and output. It omits edge-case handling (e.g., missing robots.txt, errors), but the core functionality is fully described and sufficient 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% (single 'url' parameter with clear description). The description adds that the URL is the target to check, not the robots.txt URL itself, which reinforces the schema but doesn't introduce new semantics. Baseline 3 is appropriate.

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 tool's function: fetch and parse robots.txt, then check URL permission for the wildcard user-agent. It specifies the action (check), the resource (robots.txt), and the output (verdict and matching rule). This distinguishes it from sibling scraping and extraction tools.

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 as a pre-check for URL permission against robots.txt but does not explicitly state when to use it versus alternatives. No exclusions or alternative tool mentions are provided, leaving it to the agent to infer context from sibling tool names.

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