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

Annotations already declare readOnlyHint, idempotentHint, and closed-world, so safety is covered. The description adds real value beyond them by disclosing a gating precondition (campaign must be active or paused and have a custom sequence) and by surfacing that a revision token is returned alongside the copy, which signals an edit/versioning workflow. It stops short of saying what happens when the campaign fails those conditions or what the revision is used for.

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 dense sentence with the payload front-loaded and the eligibility constraint trailing as a qualifier. No filler, no restatement of the title.

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 compensates by enumerating the three returned items (message copy, revision, custom fields). Combined with the eligibility constraint, this is nearly sufficient for a one-parameter read tool; only the failure behavior for ineligible campaigns and the role of the revision token are left implicit.

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 single parameter is nested under a 'params' object with no documentation. The description only obliquely implies the id identifies a campaign ('for an active or paused campaign') and never mentions the UUID format, the nesting, or that the id must reference an eligible campaign. With zero schema coverage, the description should have carried this burden and does not.

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 uses a specific verb ('Returns') plus a concrete payload ('current editable message copy, revision and available custom fields'), which distinguishes it from generic siblings like getCampaign. It never names an alternative tool, but the stated eligibility scope ('active or paused campaign with a custom sequence') narrows it enough that an agent can tell it apart from getCampaignSequence or previewCampaignMessage.

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 is implied through the eligibility precondition — an active or paused campaign with a custom sequence — which tells the agent when this call will succeed. However, there is no explicit when-not guidance and no pointer to a sibling (e.g. getCampaignSequence for read-only sequence inspection) when the campaign doesn't qualify.

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