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

Goes well beyond the annotations: it warns that spend can start, describes the dry-run confirmation response shape (requires_confirmation, proposed_changes), explains that the tool fills in missing ad details before requesting platform launch, and notes that provider acceptance does not prove delivery. This is exactly the behavioral context 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?

Front-loaded with purpose and the spend warning, then walks through the confirmation flow in logical order with no filler sentences. Slightly dense, and the omitted/false restatement partially duplicates the schema default, keeping it from a 5.

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 supplies the key return states (confirmation request, validation/platform errors) and the post-acceptance caveat. An agent has enough to call it correctly and interpret the response without further documentation.

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 the baseline is 3; the description earns more by explaining that true asserts the caller's explicit authorization and that false/omitted yields a non-writing confirmation response, adding authorization semantics the schema only hints at.

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 and resource ('Launch a configured campaign by ID') and immediately adds the consequence ('This can start advertising spend'), which separates it from create_campaign or check_campaign_launch_readiness. It never names a sibling explicitly, so differentiation is inferred rather than stated.

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 clear context for the two-step confirmation flow: omitting or setting confirm_budget_impact false returns requires_confirmation and proposed_changes, true asserts explicit authorization. It does not say when to prefer check_campaign_launch_readiness or manage_campaign instead, so alternatives are left implicit.

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