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

With no annotations, the description carries the full burden of behavioral disclosure. It does state that page content is not stored, which is a behavioral guarantee. However, it doesn't disclose whether the tool makes network requests, its error behavior, timeouts, or any side effects. The description provides some context but lacks depth.

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 a single, efficient sentence that front-loads the core function and includes a useful qualifier. Every word earns its place, with no redundancy or filler.

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?

The tool has 4 parameters and no output schema, yet the description only covers one aspect (URL info) and ignores the other three parameters. There is no explanation of how host, json, or zone relate to the tool's purpose. Additionally, with many sibling tools, the lack of usage guidelines makes it incomplete for an agent to call correctly.

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 schema has 100% coverage with descriptions for each parameter, so the baseline is 3. The description adds no extra parameter information—it only mentions 'URL' implicitly. The parameters host, json, and zone are not tied to the described function, creating ambiguity, but since the schema already documents them, the description's lack of clarification is not a major penalty.

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 tool returns host, scheme, and HTTP status for a URL, which is a specific verb and resource. It also adds a clarifying note that page content is not stored. However, it doesn't explicitly differentiate from sibling tools like status-catalog or normalize-url, which might overlap in function.

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 alternatives. No mention of use cases, prerequisites, or exclusions. The note about page content not being stored is the only hint, but it's not an explicit 'use this when you need basic URL metadata' instruction.

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