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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: default TXT filtering to security-relevant entries, the honest pre-filter count, token costs, and the emitted next_calls. This goes beyond the annotations without contradicting them.

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 well-organized, with a clear front-loaded purpose statement followed by parameter details, usage alternatives, and return structure. While it contains multiple sentences, each provides needed information; minor redundancy ('honest pre-filter count') could be trimmed, but overall it earns its length.

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 description is comprehensive for a tool of this complexity. It covers rate limits (30/hr Free, 500/hr Pro), token cost, response fields, default filtering behavior, and chaining recommendations. Since an output schema exists, the listed return keys are sufficient, and the description addresses operational aspects not in structured fields.

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%, so both parameters are well-described. The description adds extra meaning by explaining the include_all_txt default filter behavior, the total_txt_records field, and how the domain parameter relates to the overall audit. This enrichment justifies a score above the baseline of 3.

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's function: 'Perform comprehensive domain audit: combines domain_report + live HTTP security headers + technology fingerprinting.' It distinguishes itself from siblings by explicitly naming domain_report as a passive-only alternative and by mentioning next_calls to subdomain_enum and ssl_check.

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 provides explicit usage guidance: 'Use when you need the full picture (recon + active checks); use domain_report for passive-only assessment.' It also explains when to pass include_all_txt=true and how to chain next_calls, offering clear context for when to use this tool versus alternatives.

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