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

Annotations already declare readOnly, idempotent and non-destructive behavior, so the bar is lower. The description still adds real value beyond them: it discloses offline operation ('No network access'), the exact normalization rules (lowercase host, dropped default port, sorted query), tracking-parameter removal, and the x402 payment requirement with the eip155:8453 rail. It omits input-constraint behavior such as rejection of URLs longer than 8192 characters.

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 definition is front-loaded with the action and the decomposition, then lists the normalized/clean outputs, then operational facts (no network, price). It is dense but every sentence earns its place; the one minor cost is that the capability list is crammed into semicolon clauses rather than being easily scannable.

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?

With no output schema, the description appropriately spells out the returned components and both normalized and cleaned forms. Combined with annotations covering the safety profile, an agent has enough to call it correctly; the only real gap is input-side detail (format validation, length limit).

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 0% and the single parameter is undocumented there, so the description must carry the load. It makes clear the tool operates on a URL but never states that the input is the `url` string, nor does it mention the maxLength 8192 constraint or expected URL format. It adds context about what the URL is decomposed into, but not about the parameter itself.

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 opens with a specific verb and resource ('Parse, normalize and clean a URL') and immediately enumerates the outputs (scheme, host, port, path, query, fragment). No sibling tool performs URL parsing, so the purpose is unambiguous and distinguishable within the list.

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?

Usage is implied by the capability list and the 'No network access' note, which tells the agent this is an offline transformation rather than a fetch. However, there is no explicit when-to-use/when-not-to-use guidance or naming of related tools (e.g., web_extract, encode) that an agent might confuse with this one.

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