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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows this is a safe, non-mutating operation. The description adds return-format context (query string as key-value map) but does not disclose error behavior for invalid URLs, which is a minor gap given the schema's protocol requirement.

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 two sentences, front-loaded with the primary action, and contains no redundant information. Every phrase contributes meaning.

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 simple, single-parameter tool with rich annotations and an output schema, the description is largely complete. It explains what the tool returns and the key constraint (protocol required). It does not discuss edge-case errors, but given the tool's simplicity and existing schema, this is acceptable.

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%; the 'url' parameter is described with the protocol requirement. The description adds output-related semantics but does not deepen parameter understanding beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 clearly states the action (parse), the resource (URL), and the specific output components (protocol, host, port, path, query parameters, hash). It distinguishes itself from siblings like url-encoder by focusing on decomposition rather than transformation.

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 the tool is used when a URL needs to be broken down into its components, but it does not explicitly state when to use this tool versus alternatives, nor does it mention any exclusions or prerequisites beyond the protocol requirement in the schema.

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