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

No annotations are provided, so the description carries the full burden of behavioral disclosure. "Parse owner and repo" implies a read-only operation, but the description does not state error behavior, response shape, side effects, or whether inputs are truly discarded. The schema's "discarded" phrases hint at non-persistence, but the tool description itself adds little behavioral transparency.

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 focused sentence with no filler. It front-loads the core action, input, and output. It could not be more concise while still stating the purpose.

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, no required parameters, no annotations, and no output schema. The description names the expected output (owner and repo), but it does not specify which parameter to provide, whether non-GitHub URLs are rejected, or what happens when irrelevant parameters are passed. The clutter of unrelated schema fields makes the definition incomplete for an agent deciding how to call 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 description coverage is 100%, so the baseline is 3. The description adds important meaning by implying the url property should be a GitHub URL, but it does not explain the relationship of the other eight parameters to the parsing task. Schema descriptions cover individual fields, but the description does not resolve why city, feed, json, path, and query are present.

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 and resource: "Parse owner and repo from a GitHub URL." This clearly distinguishes it from siblings like figma-url-shape and jira-key-shape. However, the input schema includes many unrelated properties (city, feed, json, path, query), and the url property is described generically as "HTTPS URL to normalize or cite," which slightly undermines the stated GitHub-specific purpose.

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 siblings such as normalize-url, domain-shape, or other URL/shape validators. No required parameters are indicated, so an agent cannot tell whether url is mandatory or what to do if multiple fields are provided. The description leaves usage context entirely to inference.

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