meta_ads_pixels_stats

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

No annotations are provided, so the description bears the transparency burden. It states 'Read-only,' which covers mutability, and describes the return format explicitly. It adds practical context like 'rolling time window' and the purpose of detecting pixel breaks, but does not mention potential errors, rate limits, or timezone behavior. Still, the core behavioral traits are well disclosed.

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 and front-loaded: first the main action, then the output format, then usage guidance, then an alternative. Each sentence earns its place with no filler or repetition. It is ideal for an agent to scan quickly.

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 compensates by explicitly stating the row structure. It also defines a clear use case and points to a related sibling. Minor gaps remain (e.g., timezone, date granularity, pagination), but for a monitoring/reporting tool of this complexity, the description gives enough context for correct selection and invocation.

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 baseline is 3. The description adds value beyond the schema by noting that longer periods 'cost more Graph API quota but are necessary to spot slow degradations,' which is useful operational semantics not present in the schema. The rest of the parameters are already well described in the schema.

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 opens with a specific verb and resource: 'Returns aggregated pixel-event counts over a rolling time window.' It also states the exact output shape ('array of {date, event_name, count} rows') and explicitly distinguishes itself from the sibling meta_ads_pixels_events, making the purpose unmistakable.

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 concrete guidance: 'Use this to spot unusual drops in PageView / Purchase / Lead volume that indicate a pixel break.' It also identifies an alternative tool for different needs: 'For per-event metadata ... use meta_ads_pixels_events instead.' This clearly tells the agent when to choose this tool versus an alternative.

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