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

With no annotations present, the description carries the behavioral burden. It clearly frames the operation as a parse, implying a non-destructive, non-mutating pure function. It does not describe error behavior or explicitly state that other input fields are ignored, but the schema already documents that each extra field is discarded.

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 short sentence with no filler and the key verb and object are front-loaded. Every word contributes to the agent's understanding.

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 simple pure parser, the combination of description and schema is nearly complete: the description identifies the GitHub-specific target and the schema explains what happens to each parameter. There is no explicit return-shape statement, but 'owner and repo' strongly implies the output fields, and no output schema is provided to fill that gap.

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?

All seven parameters have descriptions in the schema, so the baseline is 3. The description adds modest value by linking the `url` parameter to GitHub repository URLs, but it does not explain the role of the other fields; the schema already covers their discarded-after-check behavior.

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'), a specific output ('owner and repo'), and a specific source ('a GitHub URL'). It clearly distinguishes this from sibling shape tools like domain-shape or jira-key-shape, and it goes beyond simply restating the tool name.

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 intended use case is implied: use this tool when you have a GitHub URL and need owner and repo. However, there is no explicit when-to-use, when-not-to-use, or mention of alternatives, so the agent must infer the routing from the purpose.

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