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

With no annotations, the description carries the burden of disclosure. It does indicate a side effect ('starts sending') and calls out HIGH_WRITE, which warns about mutation severity. Still, it does not explain idempotency, what happens if the campaign is already active, or the role of confirm.

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 description is short and front-loaded with the core action. The HIGH_WRITE warning and v2 path note add useful context without padding, though the confirm behavior is a notable omission.

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 write operation with no annotations and no output schema, the description is incomplete. It lacks essential guidance on the confirm parameter, the effect of defaulting to false, and what happens if the campaign is already running, leaving an agent unable to safely invoke the tool without additional assumptions.

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%, so the description must compensate, but it explains neither campaign_id nor confirm. The v2 path note hints that campaign_id is used as a path parameter, but the critical confirm parameter's meaning and default behavior are completely undocumented.

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 states a specific verb and resource: 'Activate/resume a campaign so it starts sending.' It clearly distinguishes this tool from sibling tools like pause_campaign and update_campaign by naming the exact effect on the campaign.

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 intended use is implied by 'so it starts sending,' so an agent can infer when to call it. However, there is no explicit guidance about when not to use it, prerequisites, or how it compares to pause_campaign or resume_account.

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