get_pixels

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

No annotations are provided, so the description carries the full burden. It states 'List all' but includes a limit parameter, which creates ambiguity about whether the result set is truly all pixels. It also does not disclose whether this is a read-only operation (though 'List' implies it), nor does it mention pagination, rate limits, or any side effects. The return type is described, but behavioral nuances are missing.

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 well-structured with an Args/Returns format, the purpose is front-loaded, and it is concise. Each sentence adds value, though the formatting could be tightened, but it is efficient overall.

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 output schema exists (though not shown), the description need not detail return structure extensively, and it does state the return type. However, it does not address pagination or clarify the 'all' versus limit ambiguity, nor does it mention any prerequisites or permissions. For a simple list tool, this is adequate but not 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?

The schema has 0% description coverage, but the description compensates thoroughly. It explains act_id with an example, lists all available fields for the fields parameter with a default, and defines limit as a maximum result count. This adds significant meaning beyond the schema's bare type 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 lists all Meta Pixels associated with an ad account, with a specific verb and resource. It does not explicitly differentiate from sibling tools, but the resource (pixels) is unique and the scope is clear.

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 implies usage when pixels are needed for a given ad account, and it clearly requires an act_id. However, it does not mention alternatives, when not to use it, or any exclusion criteria. The context is clear but no guidance on selecting this over other list tools is provided.

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