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

With no annotations, the description bears the full burden of behavioral disclosure. It mentions a read-only fetch and restricts output to 'group counts only', but does not explain error handling, redirects, rate limits, or any side effects. The schema's 'discarded' hints add context but are not part of the description.

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?

One concise sentence that front-loads the core action and result with zero filler. It is easy to parse and appropriately sized.

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?

The description is too sparse for a schema with seven parameters, no output schema, and no annotations. It omits the most critical operational detail — which parameter identifies the robots.txt — and does not define what 'groups' means, leaving an agent guessing how to invoke it 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?

All seven parameters have descriptions, giving high schema coverage and a baseline of 3, but the description itself does not clarify which parameter (e.g., 'url' vs 'host') supplies the robots.txt target. Several schema parameters (ref, city, feed, json, path) are described as discarded and are irrelevant to the stated purpose, creating ambiguity the description fails to resolve.

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 states a specific action ('Fetch a public robots.txt') and a specific outcome ('return group counts only'), clearly identifying the resource and operation. However, it does not distinguish itself from siblings like web-fetch or fetch-status, so it stops short of a 5.

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 provides no guidance on when to use this tool versus alternatives, no exclusions, and no prerequisites. The intended use case is only implied, not explicitly stated.

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