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

With no annotations, the description carries full responsibility; it adds a meaningful privacy guarantee ('Page content is not stored') and implies a read-only check. It does not disclose network behavior, side effects, or what happens on invalid URLs, but the stated behavior is honest and non-mutating.

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?

Two short sentences, with the core function first and the privacy note second. No filler or redundancy.

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 four parameters and no output schema, this description is incomplete: it only explains the URL-related behavior, leaving json and zone semantically disconnected and giving no return-structure guidance. The privacy note is useful but doesn't fill the gap.

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 covers 100% of parameters with descriptions, so baseline is 3. The description adds no parameter-level detail beyond referencing a URL, and does not clarify the roles of host, json, and zone.

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?

States a clear action ('Return host, scheme, and HTTP status') and resource ('a URL'), and adds a distinguishing privacy note. However, it does not differentiate it from sibling tools such as normalize-url or validate-json, and the schema's extra parameters (json, zone) are unaddressed.

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 gives no indication of when to prefer this tool over siblings, nor any exclusions or prerequisites. An agent must infer usage from the name and schema alone.

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