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

The description adds no behavioral traits beyond what the annotations already provide (readOnlyHint, idempotentHint, destructiveHint). It does not disclose caching behavior, rate limits, or any other operational details. With annotations covering safety, the description contributes minimal behavioral insight.

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 extremely concise: three sentences covering purpose, function, and context. No wasted words; every sentence adds value. It is front-loaded with the core action.

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 simplicity, existing output schema, and comprehensive annotations, the description is largely complete. It explains what the tool does and its role in a broader audit. It could briefly mention that it performs a DNS record check, but the name and context already imply this.

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 all parameters are well-documented in the input schema (e.g., domain format, verbosity, force_refresh meaning). The tool description does not add any additional semantic value beyond the schema, thus baseline score 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 the tool looks up CAA records for a domain, specifying the verb 'Look up' and the resource 'CAA records'. It further explains the purpose (showing which CAs are authorized) and places it in the context of 'scan_domain audit', differentiating it from other DNS check tools among siblings.

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?

No explicit guidance on when to use this tool versus alternative tools like check_dnssec, check_dmarc, or others. The description only mentions it is 'Part of the scan_domain audit' but does not specify conditions or exclusions for its use.

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