Update campaign

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

Annotations already declare readOnlyHint=false and openWorldHint=true, so the description doesn't need to restate mutability. It adds valuable behavioral context: partial update semantics, the daily ≤ total invariant, and the money-affecting confirm=true requirement. It doesn't describe side effects like whether unmentioned fields are preserved, but the 'partial update' phrasing covers that.

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, each carrying distinct information: scope of update, constraint, and confirmation requirement. No filler or repetition of schema details.

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 mutation tool with no output schema, the description covers the key operational rules: partial update, budget constraint, and confirm flag. It doesn't explain what the response contains or how errors surface, but the absence of an output schema lowers that burden. The main gap is that campaign_id is not described, but the tool name and schema make its role obvious.

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 only 17%, so the description must compensate. It explains the meaning of name, daily_budget_amount_local_micro, total_budget_amount_local_micro, and confirm at a high level, but doesn't detail the micros unit or the exact relationship between the two budget fields beyond 'daily must be ≤ total'. The account_id is documented in the schema, but campaign_id is not explained in either.

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 states a specific verb ('update') and resource ('campaign'), and clarifies it is a partial update of name and/or budget micros. It distinguishes itself from create/delete/list siblings by the partial-update framing, though it doesn't explicitly name a sibling alternative.

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 gives clear context: only change fields the user named, and daily budget must be ≤ total. It implies when to use this tool (when updating an existing campaign's name or budget) but doesn't explicitly contrast with x_ads_update_ad_group or x_ads_set_status. The confirm=true requirement is a practical usage condition.

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