google_ads_device_targeting_set

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

With no annotations provided, the description carries full burden. It discloses that the tool performs mutations (UPDATEs existing criteria, CREATEs missing ones), iterates devices individually to avoid cascading failures, and returns a structured response. It also notes reversibility and the requirement for non-empty input. These details provide comprehensive behavioral transparency.

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 a single, dense paragraph that efficiently covers purpose, method, error handling, return format, mutation type, reversibility, constraints, and an alternative. Every sentence provides value, though it could be slightly more structured (e.g., bullet points) for quicker scanning.

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 only 3 parameters, no annotations, and no output schema, the description is quite complete. It explains the return value structure, error handling, mutation behavior, and a key constraint. It lacks details on authentication or error cases for invalid campaign_id, but these are likely handled generically.

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 coverage is 100%, so baseline is 3. The description adds significant value beyond schema: it explains customer_id fallback to environment variables, references another tool for campaign_id, and details the effect of enabled_devices (bid_modifier mapping, non-empty requirement, creation vs update). This enrichment justifies a 4.

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 toggles device delivery on a Google Ads campaign by setting bid modifiers, and it distinguishes itself from a sibling tool (google_ads_bid_adjustments_update) for fine-grained adjustments. The verb 'toggle' and resource 'device delivery on a campaign' are specific.

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 explicitly states when to use this tool (toggling device delivery) and when not to (for fine-grained non-zero bid modifiers, use the sibling tool). It also provides usage constraints like non-empty enabled_devices and reversibility, giving clear context for selection.

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