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

With no annotations, the description carries the full burden of behavioral disclosure. It only says 'Parse owner and repo', offering no details about return format, side effects, error behavior, or what happens with non-GitHub URLs. The schema hints at discarding parameters, but the description adds no behavioral context.

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 sentence with no fluff, but it is under-specified for a tool with 9 parameters. It fails to mention the key parameter or invocation details. Being concise is positive, but here it is too terse to be useful, resulting in a low score.

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 parameters, a high schema coverage, but no output schema. The description does not explain how to select the URL, what the output looks like, or whether it validates or normalizes. It is far from complete for an agent to correctly invoke the tool without opening the schema.

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%, so each parameter is documented. The tool description adds no meaning beyond the schema; it does not clarify which parameter is the GitHub URL (though 'url' is obvious). It neither adds value nor misleads, so a baseline of 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 states a specific verb ('Parse') and resource ('owner and repo from a GitHub URL'), clearly distinguishing it from sibling shape tools like 'figma-url-shape' and 'jira-key-shape'. However, it does not specify which parameter holds the GitHub URL, creating ambiguity about how to invoke the tool.

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 like 'normalize-url' or 'web-fetch'. It does not mention exclusions, prerequisites, or the fact that it only applies to GitHub URLs (implied but not stated). No when-not conditions are given.

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