google_ads_budget_efficiency

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

With no annotations provided, the description carries the full burden. It details the return structure, verdict logic (e.g., efficiency_ratio > 1.2 => EFFICIENT), and a key behavioral trait: 'Per-campaign cost/conversions come from get_performance_report — individual failures are silently treated as zero.' States 'Read-only.' No contradictions.

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 well-structured with purpose upfront, detailed return schema, behavioral notes, and alternatives. It is slightly lengthy but every sentence adds value. Appropriate length for the complexity.

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?

Despite lacking an output schema, the description fully documents the return structure (period, total_cost, campaigns array with fields and verdict logic) and edge cases (zero-cost campaigns, silent failures). Covers all necessary context for correct invocation and interpretation.

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% with descriptions for both parameters. The description does not add additional meaning beyond the schema; it focuses on return values. Baseline 3 is appropriate as the schema is comprehensive.

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's purpose: 'Score budget allocation efficiency across every ENABLED Google Ads campaign.' It uses a specific verb ('score') and resource ('budget allocation efficiency') and distinguishes from siblings like google_ads_budget_reallocation and google_ads_budget_update.

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 provides explicit guidance on when to use this tool vs. alternatives: 'For a concrete DECREASE/INCREASE reallocation plan use google_ads_budget_reallocation; to change a single budget use google_ads_budget_update.' It also notes the tool is read-only.

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