Enable or pause a Meta Ads campaign

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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, and the description does not contradict them. The description adds meaningful behavioral context by warning that this tool controls ad spend — a consequential side effect beyond what annotations express. It does not cover failure modes or timing, but the safety profile is well covered by annotations.

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 short sentences with no filler. The action is front-loaded, and the second sentence earns its place by providing an exclusivity and consequence signal that helps tool selection and 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 simple two-parameter setter with a clear enum and strong annotations, the description is nearly complete: it states the action, the spend consequence, and why this tool is unique among siblings. It does not describe return values, but with no output schema and a straightforward status-setting operation, that is a minor gap rather than an obstacle.

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%, so the description must compensate. It partially does: 'Enable or pause' maps directly to the status enum values ACTIVE and PAUSED, and the spend warning clarifies the impact of ACTIVE. However, it does not explain campaign_id format or any edge cases, leaving some semantics to be inferred from parameter names alone.

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 gives a specific verb-resource pair ('Enable or pause a Meta campaign') and adds the exclusivity claim 'The only tool that can turn spend on,' which clearly distinguishes it from sibling read/list tools and the Google Ads status setter. An agent can immediately tell what this tool does and how it differs from nearby alternatives.

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?

The exclusivity statement 'The only tool that can turn spend on' gives clear routing for the primary use case: activating or pausing a Meta campaign's spend. It does not explicitly name alternatives or state when not to use this tool, but the uniqueness claim is strong enough for an agent to select it over the listed siblings.

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