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 but only says 'parse.' It does not state what happens for invalid or non-GitHub URLs, whether the URL is validated, what the return shape is, or that parameters other than the URL appear to be discarded. The generic schema entries like 'discarded after the shape check' add confusion rather than clarification.

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 wasted words; it states the action, input domain, and output concept immediately.

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 tool with nine optional parameters, no output schema, and no annotations, the one-sentence description is insufficient. It does not clarify the input contract, what owner/repo are returned as, or error behavior, so an agent cannot fully predict how to invoke or interpret the 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 some meaning by clarifying that the relevant input is a GitHub URL and that owner/repo are the intended outputs, but it never explicitly names which of the nine optional parameters should be populated, and the schema's `url` description says 'HTTPS URL to normalize or cite' rather than 'GitHub URL to parse.'

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 and resource: 'Parse owner and repo from a GitHub URL.' This clearly states the tool's function and, combined with the name 'github-repo-shape', distinguishes it from sibling shape tools like 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 a clear use case: use this tool when you have a GitHub URL and need owner/repo extracted. However, it gives no explicit when-not-to-use guidance or alternative routing among the many sibling URL/shape tools, so the agent must infer the boundary.

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