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

Annotations already cover read-only, idempotent, non-destructive, and closed-world, yet the description adds genuinely non-derivable behavioral context: it persists nothing so it can be repeated, sentToday spans a rolling 24 hours rather than a calendar day, and firstDayCapacity is a ceiling rather than a forecast. Those caveats prevent an agent from misreading the response.

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 lead sentence front-loads the return contents well, but "Saves nothing. It saves nothing, so it can be repeated." is a literal duplication that wastes a full sentence. The field-caveat sentences earn their place; the redundancy does not.

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, the description usefully sketches the returned sections and flags two easily misread fields. But it omits the shape of the nested body parameter, says nothing about authorization or per-campaign prerequisites beyond the required preview version, and gives no guidance on error or blocked-readiness states.

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 0%, and the description never mentions either parameter. It does not explain that params.id is the campaign UUID, nor what the free-form body object is for or whether it is required for meaningful results, so with two undocumented parameters the description fails to compensate.

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 names a specific verb and resource ("Returns launch readiness for a campaign") and enumerates the scope it covers: audience eligibility, sender health and capacity, sample recipients, and the required preview version. That enumeration distinguishes it from narrower siblings such as getSendForecast, previewCampaignAudience, or getCampaign without opening any schema.

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?

Usage context is clear from "launch readiness" and the title's "before launch," so an agent knows this is the pre-launch gate check. However, it never names an alternative or states when-not to use it (e.g., use getSendForecast for a forecast, previewCampaignAudience for a plain audience preview), leaving routing to inference.

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