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 burden. It declares 'Read-only', lists returned metrics, warns about rejected breakdown combinations, and notes quota costs for longer periods. It lacks mention of pagination or limit behavior, but is otherwise thorough for a read-only data retrieval tool.

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 just a few sentences, front-loaded with the main action. Every sentence adds value—purpose, metrics, read-only note, and sibling references—without any fluff. Highly efficient.

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?

No output schema, but the description lists all returned metrics. It covers breakdown options and period format comprehensively. While missing details on pagination or errors, it provides sufficient context for a single-call breakdown tool with 4 parameters.

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 the schema already documents parameters. The description adds value by explaining the breakdown parameter's allowed combinations and caveats, and elaborates on the period parameter with examples and quota implications, going beyond bare 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 clearly states the tool pulls delivery metrics for a campaign broken down along one dimension, listing specific breakdown options. It distinguishes from sibling tools by naming meta_ads_analysis_audience and meta_ads_analysis_placements as alternatives for pre-packaged splits, making its unique purpose evident.

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 explicitly tells when to use this tool (for ad-hoc slicing) and when not to (use dedicated tools for pre-packaged splits). It also provides guidance on breakdown combinations and period formats within the schema descriptions, offering clear context for appropriate usage.

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