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

There are no annotations, so the description carries the full burden of behavioral disclosure. It only states 'Parse owner and repo' but does not disclose what the return object looks like, whether invalid URLs cause errors, whether any side effects exist, or that the operation is read-only. For a tool with zero annotations, this is a substantial gap.

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, terse sentence with no filler. The core purpose is front-loaded and the sentence earns its place. There is no unnecessary repetition of the tool name or schema fields.

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?

Given nine parameters, no output schema, and no annotations, the description is too sparse. It does not specify which parameter must be populated, what the returned owner/repo representation is, or how the other automatically discarded parameters affect behavior. The schema's own description for `url` ('HTTPS URL to normalize or cite') does not even align clearly with GitHub parsing, so an agent is left with ambiguity about how to invoke the tool correctly.

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 coverage is 100%, so the baseline is 3. The description adds GitHub-specific meaning to the generic 'HTTPS URL' parameter by implying it should be a GitHub repo URL and that owner/repo are extracted. It does not explicitly name the `url` parameter, and the other parameters are described as discarded in the schema, so the description adds some but not full value.

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 and resource: 'Parse owner and repo from a GitHub URL.' It clearly indicates the input domain (GitHub URL) and the output concept (owner and repo), which distinguishes it from sibling tools like figma-url-shape and jira-key-shape. This is enough for an agent to know what this tool does.

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 purpose sentence implies the usage: call this when you need owner and repo extracted from a GitHub URL. However, there is no explicit guidance on when not to use it, no mention of alternatives, and no selection criteria relative to the sibling tools. It is a minimal implied usage rather than a thorough guideline.

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