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

With no annotations provided, the description carries the full burden. It discloses one behavioral trait: 'Page content is not stored.' This hints that it doesn't fetch/store full page content, which is useful. However, it doesn't mention whether it makes network requests, potential side effects, rate limits, or error behavior. For a tool that likely performs network I/O, this is a moderate gap.

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 extremely concise—two short sentences with no wasted words. It front-loads the primary purpose and adds one relevant behavioral note. Every sentence earns its place.

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?

Despite being simple, the tool has four parameters and no output schema, so the description must explain how they are used and what the return looks like. It fails to mention the 'json' and 'zone' parameters at all, nor does it describe the return format (e.g., a JSON object with host, scheme, status). The lack of usage guidance further reduces completeness. An agent would struggle to know how to invoke this tool correctly, especially given the odd parameters.

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 already explains all four parameters. The description adds minimal value by implying the 'url' parameter is the main input for retrieving host/scheme/status, but it doesn't clarify why 'json' and 'zone' parameters exist or how they relate to the tool's purpose. Since coverage is high, the baseline of 3 is appropriate, but the description could have better connected the parameters to the stated function.

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 action: 'Return host, scheme, and HTTP status for a URL.' This is a clear verb+resource+output combo, and it distinguishes the tool from siblings like normalize-url (which likely just normalizes) and http-301 (which focuses on redirects). However, it doesn't explicitly name alternatives, so it doesn't fully differentiate itself from all siblings.

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?

There is no guidance on when to use this tool versus the siblings. The description only says what it does, not when to prefer it over normalize-url, status-catalog, or others. The only hint is that it returns host, scheme, and status, which implies a specific use case, but no explicit conditions or exclusions are provided.

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