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

With no annotations, the description carries the full behavioral burden, yet it describes only the GitHub URL path. The schema reveals the tool accepts eight other unrelated inputs (city, feed, json, path, host, query, ref, timezone) with 'discarded after' semantics, which the description omits entirely. The description presents a narrow parser while the schema shows a multi-purpose shape-checker.

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 efficient and front-loaded, but it is under-specified for a tool whose schema covers nine unrelated input types with side effects (discarding). It earns credit for brevity but loses credit for not representing the tool's actual scope.

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?

For a tool with nine parameters, zero annotations, and no output schema, a one-sentence description is insufficient. An agent cannot tell what the tool returns, how the nine parameters relate to one another, or whether GitHub parsing is the only behavior versus one branch of a generic validation dispatcher.

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 schema fully documents all nine parameters including their discard behavior. The tool description adds no per-parameter meaning beyond tying the purpose to the url parameter, which matches the baseline for full schema coverage.

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 names a specific verb ('Parse') and resource ('GitHub URL') with an explicit extraction target ('owner and repo'). The resource type differentiates it from sibling shape tools like figma-url-shape and jira-key-shape without needing to open their schemas.

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 description implies when to use it — whenever a GitHub URL needs owner/repo extraction — but it never states when not to use it or names alternatives such as normalize-url, figma-url-shape, or domain-shape. The usage context is inferable but not explicit.

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