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

No annotations are provided, so the description must carry the behavioral burden. It conveys a non-mutating parse operation, but it does not disclose return format, error behavior for non-GitHub URLs, or the fact that other schema fields are ignored/discarded. The schema property notes fill some of this gap, but the description itself is thin.

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 one short sentence, front-loaded with the action and target, with no filler or redundant phrasing.

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 the noisy seven-property schema, no annotations, and no output schema, the description is slightly too terse: it does not tell the agent which field to populate or what the result looks like. The shape-check and discard behavior is only discoverable from property-level descriptions. Still, for a trivial parser, the basic invocation context is present.

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?

With 100% schema coverage, the baseline is 3, but the description adds domain specificity beyond the schema: it tells the agent that `url` is the GitHub URL to parse, whereas the schema's `url` description merely says 'HTTPS URL to normalize or cite'. This reduces ambiguity among the seven string fields. It does not explicitly map to the parameter name, but the connection is clear.

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 names a specific verb ('Parse'), the target resource ('owner and repo'), and the source domain ('a GitHub URL'). This clearly distinguishes github-repo-shape from sibling shape tools like domain-shape, jira-key-shape, or normalize-url.

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?

It identifies a clear context for use: when the agent has a GitHub URL and needs owner/repo extracted. It does not explicitly name alternatives or exclusion cases, but the GitHub-URL scope is enough to route among shape tools. No misleading guidance is present.

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