dmarc_check

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

No annotations are provided, so the description must carry the full burden of disclosing behavior. It only says 'Look up and parse' and parameter details, but does not explicitly state that it is a safe read-only operation, describe error behavior (e.g., what happens if no DMARC record exists), or mention any side effects or limitations.

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 action line plus two bullet points, with no unnecessary words. It is front-loaded and directly to the point.

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 is simple, an output schema exists, and the description covers both parameters and the action. However, the absence of annotations means it would benefit from explicitly stating that it is read-only or how it handles missing records. Overall, it is sufficient for basic use.

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?

The input schema has 0% description coverage, but the description compensates by documenting both parameters: 'domain' with an example and 'dns_server' with a default value. This adds clear meaning beyond the bare schema.

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 specifies the action 'Look up and parse' the 'DMARC record for a domain', which is specific and distinct from sibling tools like spf_check, mx_check, or dkim_check that handle other record types.

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 phrase 'Look up and parse the DMARC record' clearly implies when to use this tool (for DMARC checks), but it does not explicitly name alternatives or state when not to use it. It provides clear context without exclusions.

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