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

With no annotations provided, the description carries the full burden of disclosing behavior. It states only that it parses owner and repo, but gives no information about error handling (invalid URLs), return format, side effects, or whether it is read-only. It also does not clarify that the 'url' parameter is the primary input, nor why the schema includes unrelated parameters like 'city' and 'feed'. This is a significant gap for a tool with no annotations.

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, concise sentence that directly states the tool's function. It is front-loaded and contains no fluff. Every word earns its place.

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 is simple but has 9 parameters, many of which are irrelevant to its stated purpose (e.g., 'city', 'feed', 'host'). The description does not explain why these parameters exist or how they interact with the core function. Additionally, there is no output schema, so the agent is left without information on what the tool returns (e.g., an object with owner and repo). Given the complexity introduced by the extra parameters and the lack of output details, the description is incomplete.

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 does not add any parameter-specific meaning; it only refers to 'a GitHub URL' without elaborating on the 'url' parameter. The schema's description for 'url' says 'HTTPS URL to normalize or cite', which is somewhat inconsistent with the tool's purpose of parsing owner and repo. The description does not compensate for this discrepancy, so it remains at baseline.

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 is specific: 'Parse owner and repo from a GitHub URL.' It clearly names the verb (parse), the resource (owner and repo), and the input type (GitHub URL). It distinguishes itself from other shape tools like figma-url-shape or jira-key-shape by focusing on GitHub URLs. The purpose is unambiguous.

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 provided on when to use this tool versus its siblings. The description does not mention when it should be preferred over other shape parsers (e.g., domain-shape, normalize-url) or any exclusion criteria. The use case is implied by the name and description but not explicitly stated.

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