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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description's 'Returns' framing is consistent with that read-only profile. The description adds value beyond the annotations by disclosing the warm-up phase vocabulary (cold/warming/warmed) and the warning condition that should trigger when the profile is unvalidated or still in warm-up — decision-relevant behavior the annotations cannot convey.

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?

Four sentences with no wasted words: when to call, what is returned, the warning behavior, and the companion tool. The primary use case is front-loaded ahead of the return-value list, so an agent scanning the first sentence already knows why this tool exists.

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?

With no output schema and zero parameters, the description carries the full burden of return-value disclosure — and it delivers by enumerating domain validation status, warm-up phase, send rate cap, and throttle settings. An agent has everything needed to decide when to invoke it and how to interpret the result, including a caveat condition.

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 tool has zero parameters and schema coverage is 100%, so the 0-params baseline of 4 applies — there is nothing to document. The description instead clarifies what the caller receives, which is the semantically meaningful content for this tool.

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 ('verify the tenant is ready to send email') tied to an explicit resource (the tenant sending profile), then enumerates the returned data: sender domains and validation status, warm-up phase, send rate cap, and throttle settings. The 'before creating a campaign' framing distinguishes it from the many sibling get/list tools, and it is further differentiated from nevent_get_suppressions_summary, which is called out by name.

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 an explicit when-to-call rule ('before creating a campaign') and a conditional downstream action ('warn the user before scheduling a large campaign' if the profile is not validated or still warming). It also names the sibling to combine with (nevent_get_suppressions_summary) for a full deliverability health check, so an agent is never left to infer placement.

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