parse_url

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

With no annotations provided, the description carries the burden of behavioral disclosure. It does specify the full return key set and confirms this is a pure parsing operation, but it does not explain behavior on invalid URLs, edge cases, or what 'cost_usd' implies. This is adequate but not richly transparent.

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 efficiently structured with a one-sentence summary, a bullet-style component list, and Args/Returns sections. Every part adds useful information and nothing is redundant.

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 single-parameter parse utility with no output schema, the description provides the parameter meaning, an example, and a complete list of return keys. Minor omissions like error handling and cost semantics prevent a perfect score, but the tool is simple enough that the description is largely sufficient.

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?

The input schema gives zero description coverage, so the description must compensate. It provides a clear purpose for the 'url' parameter and a concrete example URL, which is enough for an agent to understand the expected format.

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 a URL into its components,' and then enumerates exactly which components are extracted. This clearly distinguishes it from sibling tools like parse_user_agent, which parses user-agent strings instead of URLs.

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 intended use is strongly implied by the tool name and summary, but there is no explicit when-to-use or when-not-to-use guidance, and no alternatives are mentioned. An agent can infer usage, but the description does not actively steer the decision.

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