google_ads_bid_adjustments_update

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

Discloses mutating nature, FieldMask-based partial update, and that other fields are preserved. Specifies range constraints (0.1-10.0) and behavior outside range (ValueError). Reversibility stated. No annotations provided, so description carries full burden; slightly lacks permission/authentication details but covers key behavioral aspects.

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 concise sentences covering purpose, behavior, and constraints. No redundant information. Well-structured with clear separation of concerns.

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 no output schema or annotations, description provides return value, usage guidance, parameter semantics, and links to sibling tools. Could mention error handling for non-existent criteria, but overall sufficiently complete for a mutation tool.

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. Description adds value by explaining bid_modifier values (e.g., 0.1=-90%, 1.0=neutral, 10.0=+900%) and how to obtain campaign_id and criterion_id via other tools, exceeding schema documentation.

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?

Clearly states 'Update the bid_modifier of a single campaign_criterion', specifying verb and resource. Distinguishes from sibling google_ads_device_targeting_set by noting that tool handles bid_modifier 0.0 for toggling. Explicit return value {resource_name}.

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?

Explicitly states when to use (update bid_modifier) and when not to use (toggle device on/off, directing to google_ads_device_targeting_set). Also mentions reversibility via another call, providing clear context for decision-making.

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