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

Annotations already indicate this is a mutating operation (readOnlyHint=false), and the description adds meaningful behavior beyond that: amounts are provided in account currency and internally converted to micros, and bulk execution is supported. It does not mention idempotency or exact effects, but it offers useful operation semantics not present in the structured fields.

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?

The description is concise, front-loaded, and every sentence adds value: the first states the core operation and amount format; the second covers bulk support. No filler or redundancy remains.

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 and rather sparse annotations, the description covers the main required inputs and the currency conversion behavior. It still leaves ambiguity around optional parameters (account, customer_id) and does not clarify how singular and plural forms interact in batch use.

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 must compensate for parameter meaning. It explains amount formatting and the use of campaign_ids/customer_ids for bulk, but it leaves account, customer_id, and the relationship between singular and plural parameters under-specified.

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 opens with a specific action, 'Update the daily budget of a campaign,' and clearly identifies the inputs (campaign id and new amount). It distinguishes itself from sibling tools like google_ads_campaign_budget_create and google_ads_campaign_update_status by focusing on daily budget modification.

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 clearly conveys when to use the tool (for updating a campaign's daily budget) and even notes bulk execution via campaign_ids and customer_ids. However, it does not explicitly state when not to use it or name alternative tools for other budget/status operations.

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