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

The description adds substantial context beyond the binary annotations: it does not verify a conversion event, returns the exact base-code snippet until the pixel fires, creates nothing but the pixel asset, and guarantees zero spend. It also discloses the sensitive-tier approval behavior, which is highly valuable for agent decision-making.

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 front-loaded with the core get-or-create behavior and outputs, then gives use cases, side-effect guarantees, and approval guidance in a clearly separated bracketed note. Every sentence adds information with no filler or repetition.

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 only 2 parameters and no output schema, the description covers return values, side effects, spend implications, approval nuances, and trigger conditions. An agent has enough context to call the tool correctly and set expectations with the user.

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%, so both companyId and ad_account_id are already fully documented. The description reinforces that the tool targets the ad account's pixel but does not add parameter-level meaning beyond the schema, so baseline 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 states a specific get-or-create action on the Meta ad account's pixel, reports last activity, and lists exact outputs (pixel id and base-code snippet). It clearly distinguishes itself from sibling ad tools like create_meta_ad_draft by focusing on pixel setup rather than ad creation or budget changes.

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?

Explicit trigger conditions are given: user wants conversion ads/tracking, or a LEADS/SALES draft was refused for a missing/never-fired pixel. It also provides operational guidance about approval and not re-asking in chat. However, it does not name alternative tools or state when not to use this tool.

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