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

With no annotations, the description bears full responsibility for disclosing behavior. It only says 'Parse owner and repo' but does not mention that the tool validates URL shape, ignores the other eight schema parameters (though their schema descriptions note they are 'discarded'), or describe the return format. This lack of behavioral context is a significant gap for a tool that appears to be a validation/parsing utility.

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. The core action and resource are front-loaded, making it immediately scannable. It earns its place entirely without redundancy.

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 and no output schema, yet the description explains only the narrow action of parsing owner/repo. It does not clarify why there are 8 unrelated parameters, whether the tool is a validation 'shape' check, or what the output looks like. For a tool with this complexity and no structured annotations, the description is incomplete and leaves an agent guessing about edge cases.

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?

The schema has 100% description coverage, so the baseline is 3. The description adds no parameter-specific detail beyond the overall purpose. It implies 'url' is the key input, but the schema describes 'url' as 'HTTPS URL to normalize or cite', which is inconsistent with 'parse owner and repo'. The description does not help an agent understand how the other parameters relate to the main function.

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 clearly states a specific action ('Parse owner and repo') on a specific resource ('GitHub URL'), which distinguishes it from sibling tools like 'figma-url-shape' or 'jira-key-shape'. It directly tells the agent what the tool extracts, leaving no ambiguity about its primary function.

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 gives no guidance on when to use this tool versus alternatives. It does not mention prerequisites, conditions for selection, or when to prefer another shape-checking sibling. An agent must infer usage solely from the name and description, which is insufficient for routing.

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