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

With no annotations, the description carries the full burden for behavioral disclosure. 'Parse' implies a read-only, local operation rather than a mutation, and the schema clarifies that other fields are discarded. However, the description does not state whether the URL is fetched, how invalid URLs are handled, or exactly what result shape is returned.

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 clear sentence with no filler. It front-loads the core action and expected result, making it easy for an agent to quickly understand the tool's purpose.

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 parse tool, the description gives the essential purpose and result, and the schema explains the many discardable parameters. However, given nine optional parameters and no output schema, the description could more explicitly identify which parameter should be populated and what the owner/repo result looks like.

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 all nine parameters are already documented and the baseline is 3. The description adds only a little semantic value by clarifying that the relevant input is a GitHub URL and the extracted result is the owner and repo. It does not meaningfully elaborate on parameter usage beyond the schema.

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 action and resource: parse owner and repo from a GitHub URL. This clearly distinguishes it from sibling shape tools like figma-url-shape, domain-shape, and jira-key-shape without needing to inspect the schema.

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 makes the context clear: use this tool when the input is a GitHub URL and the needed result is owner and repo. It does not explicitly name alternatives or exclusions, but the GitHub-specific wording is enough to guide selection among the many sibling tools.

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