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

Beyond the annotations (destructiveHint=true, readOnlyHint=false), the description discloses the critical two-step activation flow (first call returns a preview, second call with confirm=true actually spends), that pausing is immediate, and the delivery dependency where a child only serves when its campaign and ad squad are on. These are exactly the behavioral facts an agent needs before mutating spend.

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, front-loaded with the irreversible action (pause is immediate) and the spend-gating confirm flow, then the cascade option. No filler or restatement of the title.

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 destructive mutation tool with no output schema, the description covers the safety-critical path (preview/confirm), the cascade semantics, and the delivery precondition. The remaining gap — what the preview response looks like — is minor given the annotations already flag destructiveness.

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 63%, so several parameters are undocumented structurally, but the description compensates for the two riskiest ones: confirm (only after user consent) and include_children (cascades the same status to all children, only valid with campaign or ad squad). It adds nothing for folder, account, or language beyond the schema.

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 names the specific operation (pause / turn on) and the resources affected (campaign, ad squad, ad), with the level enum reinforcing scope. It does not, however, distinguish itself from the sibling snapchat_set_campaign_status, which appears to overlap for the campaign case, leaving an agent to infer which to pick.

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?

It gives clear situational guidance: use include_children 'to launch a new campaign', and only call with confirm=true after the user agrees. What is missing is explicit routing versus the sibling snapchat_set_campaign_status and versus snapchat_launch_campaign for new campaigns.

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