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

Beyond the annotations, the description discloses important behavior: it stops real delivery, it cannot start or increase spend, it is available directly in chat, and it refuses when no ad campaign exists or the campaign is already paused. These details meaningfully explain the safety profile and failure conditions.

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 front-loaded with the core action and purpose, then adds the risk rationale and refusal conditions in a tight, useful way. Every sentence contributes to selection or invocation.

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 two-parameter mutation tool with full schema coverage and annotations covering read/write, idempotency, and destructiveness, the description provides enough context to call it correctly. No output schema exists, so return-value details are not needed.

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 100%, and the schema already explains both brandId and campaignId with their sources. The description adds no parameter-specific syntax or format details, so the baseline of 3 is appropriate when the schema carries parameter semantics.

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: 'Stops real delivery on an active ad campaign — the kill switch.' It also distinguishes this action from riskier campaign actions like creating, activating, or scaling, so an agent can identify it clearly.

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 explains when to use the tool: pausing is monotonically risk-reducing and therefore available directly in chat. It also gives when-not conditions ('refuses if the campaign has no ad campaign, or it's already paused'), though it does not explicitly name an alternative tool such as archive_campaign.

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