google_ads_budget_update

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

No annotations are provided, so the description carries the full burden. It discloses the mutation is reversible, returns the updated budget, affects shared budgets, and specifies the currency format. There is no contradiction with missing annotations.

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 with four sentences, each adding essential information. It is front-loaded with the action and reversibility, and every sentence earns its place without redundancy.

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 tool has 3 parameters, no output schema, and no annotations, the description is complete. It covers the return value, shared budget implications, and parameter semantics, leaving no critical gaps for agent invocation.

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 input schema has 100% coverage, but the description adds value beyond it: the `amount` is 'in the account's currency unit (JPY / USD / etc.), not micros,' and `budget_id` is clarified as returned by google_ads_budget_get. This enriches the schema meaning.

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 it 'Sets the daily amount on an existing campaign budget,' specifying the verb and resource. It distinguishes from siblings like google_ads_budget_get (read-only) and google_ads_budget_create (create new) by focusing on updating an existing budget.

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: mentions that if the budget is shared across campaigns, the change affects all, advises to call google_ads_budget_get first to check reference_count, and notes reversibility via rollback_apply. This helps the agent decide when and how to use it.

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