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

With no annotations, the description carries full burden. It states the tool fetches HTTP headers and performs security analysis, but lacks details on error behavior, permissions, rate limits beyond free tier, or whether it modifies anything. Basic behavior is clear but not comprehensive.

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 concise sentence plus a parenthetical pricing note. No redundant information; every part adds value.

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 without output schema, the description adequately explains the main function. However, it lacks details about the output format (e.g., JSON structure of headers), which would enhance completeness.

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% with one param 'url' described as 'Target URL or hostname.' The description does not add additional meaning (e.g., protocol requirements, formatting). Baseline 3 is appropriate as the schema already handles parameter documentation.

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 specific verb ('inspect/analyze') and resource ('HTTP response headers + security-header analysis') for a URL. It distinguishes itself from sibling tools like 'check_domain' or 'ssl_lookup' which cover different aspects.

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 mentions pricing and free tier ('$0.002/call ... 50 free/day'), hinting at usage context, but does not explicitly state when to use this tool over alternatives or give exclusions. No guidance on prerequisites or when not to use.

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