meta_ads_pixels_list

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly states 'Read-only' and lists the exact return fields, which is substantial for a list operation. However, it does not mention pagination behavior or potential rate limits, which are common for list endpoints, so it lacks complete transparency.

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 three concise sentences: first states the core action, second lists return fields, third gives concrete use cases. Every sentence earns its place with no redundancy or fluff.

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 absence of an output schema, the description usefully enumerates the return fields and explicitly states read-only behavior. It also provides downstream usage context. However, it does not address pagination, error scenarios, or authentication requirements, which would be valuable for complete operational context.

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 description coverage is 100% for both parameters (limit and account_id), with well-written descriptions including defaults, maximums, and required format. The tool description adds nothing beyond the schema for parameter semantics, so the baseline of 3 is appropriate.

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 the specific verb 'Lists' with the resource 'Meta Pixels' and scope 'available in the ad account', clearly distinguishing it from sibling tools like get, create, stats, and events. The return fields are enumerated, leaving no ambiguity about what the tool does.

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 states when to use this tool: to find a pixel_id before creating a WEBSITE audience (meta_ads_audiences_create) or fetching event statistics (meta_ads_pixels_stats / events). It names specific alternative tools, providing clear usage context without needing further inference.

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