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

With no annotations, the description carries the full behavioral burden, yet it only states the core parse operation. It does not disclose return format, read-only status, behavior on non-GitHub URLs, or what the other eight parameters do. The schema's repeated 'discarded after the shape check' notes even imply a shape-validation behavior that conflicts with the extraction behavior the description suggests.

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 single sentence is free of filler and efficiently worded, earning credit for conciseness. But at nine words it is under-sized for a tool with nine parameters, 26 siblings, and no annotations or output schema to supplement it.

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 high-complexity tool with 9 optional parameters, no output schema, and no annotations, a one-sentence description is inadequate. An agent cannot determine what the tool returns, which parameter carries the GitHub URL, or how malformed URLs are handled. The definition needs substantial expansion to support correct invocation.

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?

Although schema coverage is 100%, the description never maps the GitHub-URL purpose to any of the nine parameters — the agent cannot tell whether to populate url or one of the other eight. The schema's url description ('HTTPS URL to normalize or cite') actually conflicts with the description's 'GitHub URL' phrasing, and parameters like city and json appear entirely irrelevant to GitHub parsing.

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 ('Parse') and resource ('owner and repo from a GitHub URL'), which clearly separates this from sibling shape tools like figma-url-shape and jira-key-shape. However, the generic 9-parameter schema (city, feed, json, query, zone) casts doubt on whether the tool truly specializes in GitHub URLs, so it does not fully earn a top score.

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?

No guidance is given on when to use this tool versus normalize-url, domain-shape, or fetch-status — siblings that all accept URLs. With 26 sibling tools and several overlapping URL-handling capabilities, the agent must infer selection criteria entirely from the name. There is also no statement about when not to use it.

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