meta_ads_insights_breakdown

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

With no annotations provided, the description carries the full disclosure burden. It states 'Read-only' and explicitly lists the returned row contents (breakdown key plus impressions, clicks, spend, cpc, ctr, conversions, cost_per_conversion), providing useful behavioral context beyond the schema. However, it does not mention pagination, rate limits, or error behavior, so it isn't fully exhaustive.

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 compact (two sentences) and front-loaded: the first sentence states the action and included metrics, the second provides usage guidance with alternatives. No wasted words.

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 no output schema and no annotations, the description compensates by explicitly listing the returned metrics and read-only nature. It also references relevant sibling tools for different use cases. The schema covers parameter details, making the overall tool definition complete.

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 detailed descriptions for all four parameters (period formats, breakdown enum, account_id format, campaign_id). The description adds minimal new parameter information beyond the schema, aligning with the baseline of 3.

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 a specific verb ('Pulls delivery metrics for a campaign broken down along one dimension'), names the resource (delivery metrics for a campaign), and lists example dimensions and metrics. It distinguishes from siblings by naming meta_ads_analysis_audience and meta_ads_analysis_placements as pre-packaged alternatives.

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 'Use this for ad-hoc slicing; for pre-packaged splits use the dedicated meta_ads_analysis_audience (age/gender) or meta_ads_analysis_placements tools, which add interpretation.' This clearly indicates when to use this tool and when to choose alternatives.

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