Launch Performance Max

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

The annotations only declare readOnlyHint=false. The description does add two genuinely useful behavioral facts beyond that: the campaign starts paused (so it is not immediately live) and a preview confirmation is a precondition. It says nothing about required account authorization, prerequisites such as connect_ad_account, or what happens if account/brand is unset, which matters for a tool with no parameters.

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, the action front-loaded and the key caveat (starts paused, preview confirmation) immediately after. No filler, nothing redundant.

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, no meaningful annotations beyond readOnlyHint=false, and no parameters, the description carries most of the burden. It covers the critical behavioral caveats (paused start, preview confirmation) but leaves open which campaign/account is launched and whether ad-account connection is a prerequisite, which an agent launching into a multi-channel sibling family would benefit from knowing.

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?

The tool takes zero declared parameters, so per the baseline rule the schema cannot be improved on and the description is not penalized for omitting parameter detail. The open additionalProperties object means any supplied arguments are undocumented in both places, but with 0 required params this is a minor concern.

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 (Launch) plus a precisely scoped resource (Google Performance Max campaign), which cleanly distinguishes it from launch_meta_ad, launch_tiktok_campaign, launch_search_campaign and the generic launch_campaign siblings without opening any schema.

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?

Usage context is only implied: the tool is for Performance Max launches and it notes a preview-confirmation step must precede it. It never names the preview tool, nor states when to prefer this over launch_search_campaign or launch_campaign, so the agent must infer routing from the name alone.

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