update_campaign

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

Discloses that the tool only produces a preview and does not apply changes, aligning with annotations (readOnlyHint=false, destructiveHint=false). Also explains that certain parameters (like geo_target_ids) replace all existing targets, providing deep behavioral insight.

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?

Description is front-loaded with the crucial preview behavior, then systematically covers each parameter. While slightly lengthy due to parameter explanations, every sentence adds value and no extraneous content exists.

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 output schema exists, the description explains the return value (plan_id) and how to use it with confirm_and_apply. It also covers parameter interdependencies and replacement semantics, making the tool's behavior fully understandable.

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?

With 0% schema description coverage, the description fully compensates by explaining every parameter: campaign_id required, bidding_strategy enum options, conditional target_cpa and target_roas, daily_budget, geo_target_ids with common IDs, language_ids with common IDs, booleans for network settings, and max_cpc conditional. It even clarifies that display_expansion_enabled is an alias.

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 drafts an update to a campaign and returns a preview without applying it, with a specific verb and resource. It distinguishes the tool from the sibling 'confirm_and_apply' that executes the update.

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?

Provides explicit guidance on when to use the tool (only include changed parameters) and directs the user to call 'confirm_and_apply' with the returned plan_id to execute. It also explains conditional parameter requirements (e.g., target_cpa needed if bidding_strategy is TARGET_CPA).

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