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

Annotations are absent, so the description alone must disclose behavior. It says 'parse' but does not state whether the operation is read-only, what the return format looks like, whether invalid URLs raise errors, or whether any side effects occur. This is insufficient for a tool with no annotation support.

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 sentence that is front-loaded and contains no fluff. It gives the essential purpose without extraneous detail, earning a high score for conciseness even though other dimensions lack content.

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 9 parameters, no output schema, and no annotations, a one-sentence description is critically incomplete. It does not explain which parameters are relevant, how the output is shaped, validation behavior, or error handling, leaving the agent without enough information to invoke it reliably.

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% (baseline 3), and the description adds key meaning by clarifying that the URL is a GitHub URL and the intended result is an owner/repo extraction. This is not present in the generic param description 'HTTPS URL to normalize or cite'. However, it provides no guidance for the other eight parameters.

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 'Parse owner and repo from a GitHub URL' uses a specific verb (parse) and names the entity (owner and repo) plus the input source (GitHub URL). It clearly distinguishes this tool from sibling URL-shape tools like figma-url-shape and jira-key-shape, even without explicit comparison.

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?

No guidance is given on when to use this tool versus alternatives like normalize-url or other *-shape tools. There are no exclusions, prerequisites, or examples of appropriate use cases.

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