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

With no annotations, the description carries the transparency burden. It is explicit that the tool fetches a public robots.txt and returns only group counts, which sets expectations about scope. However, it does not mention error cases, redirects, user-agent behavior, or whether supplied parameters are discarded or ignored.

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 front-loaded sentence with no filler: the action, target, and return restriction are all stated. Every word earns its place.

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 tool has 9 optional parameters, no annotations, and no output schema, yet the description only names an action and return type. It does not explain what a 'group' is, which parameter supplies the target, or how errors are returned, so an agent cannot reliably invoke it.

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%, giving a baseline of 3, but the parameter descriptions are misaligned with the tool: they mention weather hints, JSON validation, search-length checks, and values 'discarded after the shape check.' None clearly identifies a robots.txt URL, and 'url' is described as 'normalize or cite,' so the agent cannot map arguments to the described fetch action.

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 verb ('Fetch'), a concrete resource ('public robots.txt'), and an explicit output ('return group counts only'). This clearly differentiates it from siblings like web-fetch or fetch-status, which fetch or check pages generally.

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?

There is no guidance about when to use this tool instead of web-fetch, fetch-status, or normalize-url, and no exclusions or prerequisites are stated. Usage must be inferred solely from the tool name and one-line action.

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