meta_ads_pixels_events

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

Since no annotations are provided, the description alone must convey behavioral traits. It states the tool is 'Read-only', describes the output fields (event_name, sample_count, first_seen, last_seen, sample_parameters), and implies it returns sample data. This is good but could be improved by mentioning data freshness or any rate limits.

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 concise, with only a few sentences. It front-loads the main action and output, then provides usage guidance in the next sentence, and ends with a comparison to a sibling. Every sentence adds value with no filler.

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 no output schema, the description enumerates the exact fields returned (event_name, sample_count, first_seen, last_seen, sample_parameters). It also explains the nature of the data (sample payloads). For a read-only list/audit tool, this is comprehensive enough.

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 both parameters described. The description adds minimal value beyond the schema: it mentions 'account_id' can fall back to credentials and confirms 'pixel_id' is required. Baseline 3 is appropriate as schema already carries the parameter details.

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 verb 'lists' and the resource 'distinct event types the pixel has received recently, with sample payloads'. It explicitly differentiates from the sibling tool meta_ads_pixels_stats by specifying that this is for auditing event types vs aggregate volume.

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 usage context: 'use this to audit which standard events... are firing, and to inspect parameter names before building conversion rules or audience definitions'. It also directly contrasts with meta_ads_pixels_stats for aggregate volume, giving clear when-to-use guidance.

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