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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the parse action but does not reveal what happens with invalid URLs, whether the tool returns an error or a success object, or why the schema includes many unrelated parameters like city and feed that appear to be discarded. The schema mentions discarding for some parameters, but that is schema-level, not description-level, and the description adds no behavioral nuance.

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, focused sentence with no filler. It is appropriately concise and front-loaded with the core action. However, it is so brief that it borders on under-specification for a tool with a complex schema, but strictly for conciseness it is efficient.

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 the tool's name and sibling context, the description is incomplete. It does not explain the presence of nine parameters when only 'url' seems relevant, nor does it describe the return value or error behavior. The mismatch between the GitHub-specific description and the generic schema creates confusion that is not resolved by the description. An agent cannot reliably determine what parameters to supply or what to expect as output.

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 no extra parameter meaning beyond the schema; it only references the 'url' parameter implicitly. Since every parameter is already documented in the schema, the description does not need to compensate, and it does not add any value beyond what the schema provides.

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 and resource, clearly indicating the tool extracts the repository owner and name from a GitHub link. It is unambiguous, but it does not explicitly differentiate itself from sibling shape tools like figma-url-shape or jira-key-shape, relying on the GitHub-specific mention to imply its niche. Thus it earns a 4 rather than a 5.

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 alternatives. The description only states what it does, not when it should be preferred over, say, a generic URL normalizer or other shape checkers. There is no mention of exclusions, prerequisites, or fallback conditions, leaving the agent to infer usage context from the name alone.

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