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

With no annotations, the description carries the full behavioral burden, but it only says 'parse' and does not disclose what happens with the many unrelated parameters, whether non-GitHub URLs error out, or what the result shape is. The schema hints that several parameters are discarded, but the tool description itself provides no transparency about these behaviors.

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 single sentence is front-loaded, direct, and contains no filler. It loses a point only because it omits contextual information that would help an agent handle the nine-parameter schema, though that omission is more relevant to other dimensions.

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?

This tool has nine optional parameters, no annotations, and no output schema, so the description needs to clarify which parameters matter and what the tool returns. The description only covers the basic parse operation and does not explain that url is the only meaningful input or what the owner/repo result looks like, leaving an agent under-informed for correct invocation.

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, but the description adds important meaning by identifying the url parameter as the operative GitHub URL and clarifying that the expected extraction is owner and repo. This is more specific than the schema's generic 'HTTPS URL to normalize or cite' description.

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 'Parse owner and repo from a GitHub URL' uses a specific verb, names the input resource (GitHub URL), and states the output (owner and repo). This clearly separates it from sibling tools like figma-url-shape, jira-key-shape, and domain-shape, which target different URL or key shapes.

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 use case is implied: call this when you have a GitHub URL and need the owner and repo parsed out. However, there is no explicit guidance about when not to use it, nor any mention of the more specific sibling tools for other URL shapes, so the guidance remains implicit rather than explicit.

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