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

Adds meaningful behavior beyond the annotations: the state transition (paused to active) and two specific failure modes (409 for invalid state, 403 for plan exclusion). Annotations already cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), and the description usefully layers on error semantics.

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 short sentences with the core state change front-loaded and preconditions following. Every sentence carries distinct information with zero filler.

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; the description supplies the state change and error conditions, which is nearly complete. Only minor gaps remain, such as rate-limit or permission nuances beyond the plan check.

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 both parameters (id and context) are already fully documented. The description adds no parameter-level detail beyond the schema, so the baseline 3 applies.

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+resource ('Resume a paused campaign') and clarifies the resulting state ('it becomes active again'), making the transition unambiguous. It doesn't explicitly name contrastive siblings like pause_marketing_campaign or schedule_marketing_campaign, but the state-based framing makes the intent clear enough to distinguish it.

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 concrete preconditions for use: the campaign must be paused and have a future end time, with the 409 outcome otherwise, plus a 403 plan restriction. This tells the agent when the call will succeed versus fail, though it doesn't explicitly route to alternative tools for the error cases.

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