google_ads_conversions_performance

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

With no annotations, the description carries the full burden. It discloses key behaviors: read-only, only rows with conversions > 0 are included, and the technical limitation that cost_per_conversion is computed separately due to GAQL constraints. It also explains the full response structure. It lacks details on authentication or error handling, but for a read-only report these are less critical.

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 information-dense but well-organized: a concise purpose statement, a detailed return shape, key filtering behavior, a technical caveat, and an explicit alternative. Every sentence adds value, though the lengthy output structure makes it less concise than ideal. Overall, it earns its place.

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's complexity and absence of an output schema, the description goes far beyond minimal by specifying the exact return objects (actions, daily_details, landing_pages) and their fields. It also explains row filtering and the GAQL limitation. It does not cover items like pagination or rate limits, but these are less likely to be significant for a reporting tool with this shape.

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 each parameter already has a descriptive schema entry (period enum with guidance, campaign_id as optional filter, customer_id with fallback). The description adds no extra parameter semantics beyond what the schema provides, so the baseline 3 is appropriate.

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 reports Google Ads conversions broken down by conversion_action and date, with an optional campaign filter. It explicitly distinguishes from sibling tools by pointing to google_ads_performance_report for campaign-level metrics, and the detailed return structure leaves no ambiguity about the tool's purpose.

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?

Usage context is clear: it's a read-only conversion breakdown tool. The description explicitly says 'For campaign-level metrics use google_ads_performance_report', providing a direct alternative. It does not mention other potentially relevant alternatives (e.g., ad performance or search terms reports), but the guidance is sufficient for distinguishing from the most likely sibling.

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