google_ads_monitoring_cpa_goal

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

No annotations exist, so the description fully discloses behavior: read-only (does not change bids), hardcoded LAST_7_DAYS window, detailed status thresholds (healthy, warning, critical with CV==0 condition), and cost_analysis integration. This compensates for missing annotations completely.

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 information-dense but front-loaded with purpose. It uses a structured return type outline, making it easy to parse. Could be slightly more concise, but the clarity compensates for length.

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, the description provides a complete return object layout with types, edge cases (None when CV==0), and links to related tools. All required aspects (parameters, behavior, return, alternatives) are covered, leaving no ambiguity.

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%, and description adds meaningful context for each parameter: explains fallback for customer_id, source for campaign_id (via campaigns_list), and threshold semantics for target_cpa (1.2x warning/critical). Goes beyond schema definitions.

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 uses specific verbs ('Evaluate', 'Integrate') and clearly states the resource (campaign's last-7-days CPA against target). It distinguishes from siblings by naming google_ads_health_check_all and google_ads_monitoring_cv_goal as alternatives, making its unique purpose clear.

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 this tool (evaluate CPA vs target) and provides alternatives for account-wide rollup (health_check_all) and daily CV-count (cv_goal). This gives clear guidance on appropriate use cases versus sibling tools.

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