check_domain_sending_records

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows this is a non-mutating call that reaches outside the system. The description reinforces that scope by naming the DNS lookups performed, but says nothing about behavior on missing/invalid records, lookup latency, or what the check reports back.

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?

A single compact sentence that front-loads the action and resource, with the record types and use case as supporting detail. Nothing is redundant, but the trailing 'for sending/replying from aliases' is slightly vague.

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?

For a one-parameter read tool with no output schema, the definition is workable but thin: it doesn't indicate what the check returns (e.g., pass/fail per record) or what an agent should do when a record is absent, which matters for a diagnostic tool.

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?

Only one parameter exists and schema coverage is 100%, so the baseline is 3. The schema's own text is generic ('The id (UUID) of the item'); the description implicitly clarifies that this id identifies the domain whose records are checked, but adds no format or sourcing detail beyond that.

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?

States a specific verb (check) and resource (a custom domain's DNS records) and enumerates the record types inspected (SPF, DKIM, DMARC). It is clearly a diagnostic read, distinct from mutation siblings like create_domain, update_domain or delete_domain, though the description never explicitly contrasts them.

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 trailing phrase 'for sending/replying from aliases' implies the scenario (verifying a domain is correctly configured before using it for alias mail), but there is no explicit when-to-use, no prerequisites such as domain ownership or prior registration, and no named alternative tool.

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