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

Goes beyond the annotations by disclosing the state precondition and the specific failure mode (409 on a non-active campaign), plus reversibility via resume. Annotations cover the safety profile (readOnly=false, destructive=false, idempotent=false); the description usefully adds the operational constraint they do not express.

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?

Two compact sentences with no filler; the effect is front-loaded and the constraint plus escape hatch follow in the right order. Every clause carries information.

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?

With an output schema present, return values need no explanation, and the description covers the precondition, error behavior, and reversal path. What is missing is minor: whether pausing preserves configuration for re-activation is implied but not stated.

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%, so the `id` and `context` parameters are already fully documented in the schema, including the cross-reference to list_marketing_campaigns. The description adds no parameter-level detail beyond that, so the baseline 3 is appropriate.

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?

States a specific verb (pause) and resource (marketing campaign) plus the concrete effect: 'it stops applying to signatures.' This distinguishes it immediately from delete_marketing_campaign and update_marketing_campaign in the sibling list.

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?

Gives a clear precondition ('Only an active campaign can be paused') and routes the agent to the follow-up action (resume_marketing_campaign). It stops short of naming the adjacent alternatives an agent might confuse this with, such as delete or schedule, so it is strong but not fully comparative.

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