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

Annotations already mark this as readOnlyHint: true, idempotentHint: true, and destructiveHint: false. The description adds that it identifies sensitive subdomains and stale records, matching the read-only audit character. However, it does not disclose any behavioral nuances beyond the annotations, such as data freshness details or the fact that 'force_refresh' bypasses cache. Score is adequate but not elevated due to good annotation coverage.

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 two sentences long, front-loads the main purpose ('Audit DNS zone hygiene'), and provides concrete examples of findings (sensitive subdomains, stale SOA records, propagation issues). Every sentence adds value, with no redundancy or filler. Highly efficient.

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 a complete output schema, so return values are already documented. The description covers what the tool does and key finding categories. Given the presence of sibling tools like check_txt_hygiene and check_subdomains, it would benefit from a brief mention of how it differs from them (e.g., 'Unlike check_subdomains, this focuses on security hygiene rather than enumeration'), but as is, it is reasonably complete.

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 documents all three parameters (domain, format, force_refresh) with descriptions. The tool description adds no additional parameter-level semantics. Baseline 3 is correct because the description does not enhance or clarify the parameter usage beyond what the schema provides.

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 audits DNS zone hygiene, identifies sensitive or forgotten subdomains, stale SOA records, and propagation issues. The verb 'audit' and resource 'DNS zone hygiene' are specific. However, among sibling tools like 'check_subdomaining' and 'discover_subdomains', it could better distinguish itself, e.g., by noting it focuses on security posture rather than discovery.

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 specifies two use cases: finding sensitive subdomains visible in DNS and auditing overall zone cleanliness. However, it does not mention when NOT to use it (e.g., if only subdomain discovery is needed, use 'discover_subdomains') nor does it reference alternative tools. Context is implied but exclusions are missing.

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