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

Annotations declare non-readonly, idempotent and open-world, and the description adds genuinely new behavioral context: the call is asynchronous, the verdict appears within about a minute, and DNS propagation itself may lag for hours. It does not mention rate limits or whether a re-check is safe to repeat, but the latency model is the key thing an agent needs.

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?

Three short sentences, front-loaded with the action, then the follow-up read, then the timing caveat. Nothing is redundant and nothing needed is buried.

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?

There is no output schema, and the description correctly tells the agent to read results via get_sending_domain and sets expectations about timing. Remaining gaps are minor: no note on permissions, retry behavior, or the shape of any immediate response.

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 coverage is 0% for the single sending_domain_id parameter, so the description should carry that meaning. It implies the domain being re-checked but never explains the ID format or where to obtain it (e.g. list_sending_domains), relying on the self-evident parameter name.

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 action on a specific resource: re-triggering the provider's DNS lookup for a sending domain. It is clearly distinguishable from get_sending_domain (which reads the result) and create_sending_domain (which sets one up), both named or implied in the sibling list.

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?

Gives the trigger condition explicitly ('after the user added the records') and routes the agent to the sibling that reads the outcome. It stops short of saying when not to call it (e.g. do not poll repeatedly) or how often it may be invoked.

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