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

With no annotations, the description carries the full burden. It accurately describes the core parse behavior, but it does not disclose how malformed URLs are handled, whether git suffixes or trailing slashes are normalized, or that unrelated schema fields are ignored. The schema's 'discarded' notes add some context, but the description itself is minimal.

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?

One sentence with no filler. The verb and target are front-loaded, and every word contributes to the meaning. This is appropriately concise.

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 9 optional parameters and no output schema, yet the description only says 'parse owner and repo.' It does not specify the output structure or warn that most schema fields are irrelevant for this tool. For such a simple operation this is minimally viable, but the unrelated parameters create real ambiguity that the description does not resolve.

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?

Parameter schema coverage is 100%, so the baseline is 3. The description does not explicitly say the GitHub URL goes in the `url` parameter, but the parameter name and its schema description ('HTTPS URL to normalize or cite') make that mapping reasonably inferable. It adds no parameter-level detail 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 ('Parse') and a specific result ('owner and repo') for a specific input ('a GitHub URL'). This distinguishes it clearly from sibling shape tools such as jira-key-shape or figma-url-shape by naming the exact resource type.

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?

No guidance is given about when to use this tool versus siblings like normalize-url, domain-shape, or browser-url-ok. It does not mention that this is a syntactic parse with no network access, nor does it state any exclusion criteria for when not to use it.

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