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 it only says 'Parse owner and repo from a GitHub URL.' It does not explain that the tool likely discards irrelevant inputs, what it returns, or how it behaves on invalid, non-GitHub, or malformed URLs. The schema's mention of 'discarded after the shape check' hints at behavior the description itself never confirms.

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 filler or repetition. It is efficient, but it is so terse that it omits important behavioral and usage context, so it is not maximally effective for an agent.

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?

Given seven optional, seemingly unrelated schema parameters, no output schema, no annotations, and no usage guidance, the description is not sufficient for correct invocation. An agent cannot determine whether to pass url, ref, or some other field to obtain owner and repo, nor what the result will look like.

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 description coverage is 100%, the property descriptions are generic and mismatched: 'url' is described as 'HTTPS URL to normalize or cite' rather than a GitHub URL to parse, and the other parameters (city, feed, host, json, path) appear unrelated to the tool's stated purpose. The tool description adds no mapping from these parameters to the parser's intended use, leaving an agent uncertain which field to populate.

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'), making the tool's primary function immediately obvious. It also distinguishes it from sibling shape tools like domain-shape, figma-url-shape, and jira-key-shape by naming the GitHub context.

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 on when to use this tool versus alternatives such as normalize-url, domain-shape, or other URL-oriented tools. The description implies usage when a GitHub URL is present, but it does not state any when-to-use conditions, exclusions, or alternative tools.

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