meta_ads_pixels_list

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

No annotations provided, but the description declares the tool as 'Read-only' and lists the exact fields returned, giving sufficient behavioral context for a simple list operation. It could mention default pagination or empty results, but the provided info is adequate.

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?

Three sentences, each with specific value: purpose + return fields, read-only declaration, and usage guidance. Front-loaded with the most important information and no unnecessary words.

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?

For a straightforward list tool with two parameters and no output schema, the description covers all essential aspects: purpose, returned data, read-only nature, and context for use with related tools. Nothing is missing for effective use.

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?

Input schema covers 100% of parameters with clear descriptions. The description does not add new semantic information about parameters beyond what the schema already provides, so baseline score 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 clearly states 'Lists Meta Pixels available in the ad account' and specifies the exact fields returned (id, name, code, last_fired_time, is_created_by_business), distinguishing it from sibling tools by naming specific use cases.

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?

Explicitly tells when to use this tool ('Use this to find a pixel_id before creating a WEBSITE audience or fetching event statistics') and names specific sibling tools (meta_ads_audiences_create, meta_ads_pixels_stats, events), providing clear guidance on alternatives.

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