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

Goes well beyond the annotations by explaining the spend consequences of each direction, the refusal rule for externally-set statuses (e.g. paused by budget), and that the previous status is returned so the change is reversible. This is exactly the mutation-risk context the destructiveHint alone cannot convey.

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?

Five tight sentences, front-loaded with the core action and effect, then constraints, then rollback and dry-run guidance. No filler or repetition.

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 no output schema, the description compensates by stating the return value (previous status) and the refusal semantics. Combined with full schema coverage, an agent has everything needed to call this safely.

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%, so every parameter is already documented, including the same conditional campaignId/adGroupId requirements the description restates. The description adds no format or constraint detail the schema lacks, so 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 pair (pause/resume) and the exact set of resources it applies to (campaign, ad group, keyword, ad). An agent can immediately distinguish it from bid/budget setters and from generic status updaters 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 concrete preconditions: only Active and Paused are accepted, other states are refused rather than overridden, and dryRun should be used when unsure. It does not name a sibling alternative (e.g. the campaign-level update tools), so it stops short of full routing guidance.

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