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

With no annotations, the description carries the behavioral transparency burden. 'Parse' suggests a local, read-only operation, but the description does not disclose the return shape, how malformed or non-GitHub URLs are handled, or that many of the schema's nine parameters are discard-only. It is minimally transparent but not misleading.

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, front-loaded sentence with no filler. It communicates the essential behavior efficiently and is appropriately concise for a simple parsing utility.

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 nine optional parameters, no annotations, and no output schema, so the one-sentence description is insufficient for fully guided invocation. It does not state the return format, which parameter is required in practice despite all parameters being optional in the schema, or what happens when the supplied value is not a valid GitHub URL.

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 adds the key meaning that the URL should be a GitHub URL and that owner/repo are the extracted values, but it does not clarify how the other eight accepted parameters relate to this tool or which parameter is the actual input for invocation.

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 uses a specific verb and resource: 'Parse owner and repo from a GitHub URL.' It clearly identifies what the tool does and is distinct enough from siblings like figma-url-shape or jira-key-shape, though it does not explicitly name or contrast those alternatives.

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 phrasing implies the tool should be used when an agent has a GitHub URL and needs to extract owner and repository names. However, it does not explicitly state when not to use it, what inputs are prerequisites, or how it differs from alternatives like normalize-url or web-fetch.

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