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

Annotations already declare readOnlyHint=false, openWorldHint=false, and destructiveHint=false, so the agent knows this is a non-read-only but non-destructive mutation. The description only adds the precondition that the campaign must be running; it does not explain reversibility, side effects, permissions, or what happens if the campaign is already paused.

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 a single front-loaded sentence with zero waste, which is highly concise. However, for a tool with three required undocumented parameters, it is arguably too thin rather than optimally sized.

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?

Given three required parameters with no schema descriptions, no output schema, and sibling tools that perform related state changes, the description should at least indicate which identifiers are needed or how pausing relates to cancel/resume. It does neither, leaving important context to inference.

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 schema has 0% description coverage for three required parameters (projectId, siteId, campaignId), and the description never mentions any of them. It adds no meaning beyond the bare parameter names in the input schema.

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 gives a specific verb (pause) and resource (campaign), and the title/name clarify it is a distribution campaign. It does not distinguish the tool from siblings like cancel_distribution_campaign or resume_distribution_campaign, so it is clear but lacks sibling differentiation.

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 phrase 'a running campaign' implies the tool should be used when a campaign is currently running, giving minimal prerequisite context. However, it does not explicitly say when to use this versus cancel, resume, or update, and it offers no alternative guidance.

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