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

Annotations declare destructiveHint=true and idempotentHint=false, and the description honors this by warning that messages already sent are not recalled. It also discloses the operational semantics (messages stop, administator-only resume, dashboard-only resume path) that annotations cannot convey, and the description does not contradict any hint.

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 sentences, each earning its place: effect, non-recall caveat, and intended use case. The critical constraint (no further messages go out) is front-loaded after the verb.

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 single-parameter mutation tool with no output schema, the description covers what the agent needs: scope, reversibility, side effects, resume path, and legitimate trigger conditions. Nothing material is missing given the annotation coverage.

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 100% and the single parameter is fully documented ('Campaign id as returned by list_whatsapp_campaigns'). The description adds no parameter syntax or format details beyond the schema, which is the expected baseline for a high-coverage single-param 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?

The description opens with a specific verb+resource ('Pause a running WhatsApp campaign') and immediately defines the operation's consequence ('no further messages go out until an administrator resumes it'). It's clearly distinguishable from siblings like cancel_whatsapp_campaign and pause_voice_campaign by naming the channel and the pause-vs-cancel semantics.

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?

It gives an explicit when-to-use condition ('when a campaign is hurting the number (many failures, complaints, a wrong template)') and tells the agent where the inverse operation happens ('Resuming happens in the dashboard'). The alternative (cancel) is implicitly contrasted by the reversibility statement.

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