contrast_scan

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

Beyond annotations (readOnlyHint, etc.), the description discloses the active outbound fetch, per-target eTLD+1 throttle at 60 req/min, credit costs per plan (free vs pro), and the enrichment process. This adds significant behavioral context that annotations alone do not provide.

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 dense but efficient, front-loading the main purpose and then listing modules, usage, throttle, credits, and return fields. While it could be slightly more structured (e.g., bullet points), it remains concise without unnecessary words.

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?

Given the tool's complexity, the description covers purpose, modules, usage, throttle, credits, and enumerates all return fields. Combined with the input schema and annotations (including output schema existence), the description provides comprehensive context for correct tool invocation.

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?

Only one parameter (domain) with 100% schema coverage, and the schema already provides a good description including constraints (no protocol/path, reject bare IPs/private domains). The description does not add additional semantic meaning beyond the schema, so baseline of 3 is appropriate.

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 it performs an active website security scan with a specific set of 11 modules and enriches results with vulnerability findings and a letter grade. It distinguishes from sibling tools like audit_domain and scan_headers by specifying different use cases.

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?

Explicitly states when to use this tool (hands-on misconfiguration scan) and when to use alternatives (audit_domain for passive recon, scan_headers for headers only). Also mentions per-target throttle and credit costs, providing complete usage context.

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