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

Annotations already declare destructiveHint=true, idempotentHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavioral facts: the effect is a spend reduction, it acts on the provider, and a human approval gate applies before execution.

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?

One compact sentence, front-loaded with the verb and resource, with the precondition, identifier options, effect and approval requirement packed in without 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?

For a two-parameter mutation with full annotation coverage and no output schema, the description covers effect, precondition and approval. Minor gaps remain: behavior when the campaign is not ACTIVE, and whether exactly one identifier must be supplied.

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 0% and both parameters are optional with no required constraint, so the description must carry the load. It does identify the two accepted identifiers and implies either is acceptable, but it never states that at least one is required, nor the format/uuid version.

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?

Specific verb (pause) plus resource (ad campaign) plus scope ('ACTIVE', 'on the provider'), and the bracketed '[publish]' tag flags the category. It never names the inverse sibling activate_ads_campaign, so an agent must infer the pairing, which keeps it out of the top band.

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?

'ACTIVE' implies a precondition and 'Requires human approval' states a real prerequisite, so usage context is present but implicit. There is no explicit when-not guidance (e.g. what to do for a PAUSED campaign) and no named alternative tool.

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