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

Annotations already mark it as read-only and non-destructive, but the description adds important behavioral context: the data is sourced from a once-daily turbocheck report, the response includes a timestamp, and recent record changes may be delayed. This goes well beyond the structured annotations.

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 front-loaded with the tool's purpose, then adds the freshness caveat and the alternative in a compact way. Every sentence earns its place and nothing is wasted.

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 simple one-parameter schema, read-only annotations, and no output schema, the description provides everything needed: what is retrieved, when cached data may lag, and which sibling to use for live results. No critical invocation detail is missing.

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%, and the single domain parameter is already documented in the schema. The description implies the domain input but adds no syntax or format detail beyond what the schema provides, so the baseline 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 gives a specific verb and resource: retrieve a domain's DNS mail security settings, explicitly listing SPF, DKIM, DMARC and MX. It also distinguishes the tool from the sibling get_dns_records by naming that alternative for live data.

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?

It clearly explains when to use this tool: for data from the daily turbocheck report, with the caveat that newly set records may not appear until the next run. It names the explicit alternative get_dns_records for immediately reliable live DNS data.

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