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

With no annotations, the description carries the full burden. 'Parse' makes the core read-only behavior clear, but the description does not disclose invalid-URL behavior, whether non-GitHub URLs are rejected, or what exactly is returned when parsing fails.

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?

A single front-loaded sentence with no filler. The verb, target, and input type are stated immediately, and every word contributes.

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 adequate for a simple parse operation, but the schema contains many optional parameters that are never mentioned, and there is no output schema or annotation to clarify return shape and edge cases. An agent may still be unsure whether fields like `ref` or `path` are relevant to this GitHub-specific tool.

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 meaning beyond the schema by identifying the `url` parameter as the GitHub URL to parse and clarifying that the expected output is owner and repo, which the generic 'HTTPS URL to normalize or cite' schema text does not convey.

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 ('parse') and a specific resource ('owner and repo from a GitHub URL'). This clearly distinguishes the tool from sibling shape tools such as domain-shape, figma-url-shape, and jira-key-shape.

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 implies when to use the tool: whenever a GitHub URL needs to be converted into owner and repo. However, it gives no explicit conditions, exclusions, or comparisons to alternatives such as normalize-url, so the agent must infer the selection logic.

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