Update a campaign (draft|paused only)

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

With no annotations provided, the description carries the full burden. It discloses the trinary semantics for nullable fields (omit, null, set) and the side effect of invalidating preview tokens on certain edits. This goes beyond basic mutation behavior, though it does not cover error responses or idempotency.

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 sentences, each earning its place: first states purpose and constraint, second explains nullable field semantics, third details side effects. No fluff, highly efficient.

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?

Given the complex schema (13 params, nested objects) and lack of annotations or output schema, the description covers essential operational details (state constraints, trinary semantics, preview token invalidation). It could improve by briefly mentioning the response type, but the core completeness is solid.

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 compensates with the trinary semantics rule, which is critical for correct use of nullable fields. It also explains the preview_token invalidation tied to specific parameter groups. However, it does not detail individual parameters beyond that, leaving some interpretation for nested objects.

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 clearly states the tool patches a campaign with a specific verb ('Patch') and resource ('campaign'). It immediately adds crucial state constraints ('ALLOWED only in `draft` or `paused` state'), which distinguishes it from siblings like campaign_create, campaign_launch, and campaign_archive.

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 description explicitly restricts when the tool can be used (only draft/paused states) and warns about preview_token invalidation when editing audience, channels, or creative. While it could mention alternatives like campaign_create for new campaigns or campaign_launch to change state, the context is clear given sibling names.

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