Reddit pixels

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

Annotations already mark the tool as read-only and non-destructive. The description adds behavioral value by explaining that the output reports last-fired event times and can be used to identify pixels and ad groups with no matching event history. It does not mention pagination or authentication edge cases, but those are minor for this simple read operation.

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 short sentences, front-loaded with the core function and followed by actionable usage guidance. Every sentence earns its place and there is no filler or redundant restatement of the schema.

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 single-parameter read-only tool with an output schema, the description is nearly complete: it states what is returned, why to call it, and the operational consequence of missing pixel events. The only real gap is the unresolved behavior of ad_account_id and its default value.

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 contains only ad_account_id with a default value and 0% description coverage, so the description must compensate but only loosely ties the parameter to 'the account'. It does not clarify whether the default empty string selects a default account or whether the ID should come from list_reddit_accounts first.

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 verb and resource: it retrieves Reddit pixels and the last-fired time for each event such as purchase, sign_up, and lead. It also distinguishes itself from sibling entity tools by focusing on pixel-level data and the concrete role of providing conversion_pixel_id values.

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 gives explicit guidance on when to use the tool: 'Run before conversion-optimized campaigns' and explains why: to flag pixels that never fired and ad groups optimizing for events their pixel has never sent. It does not name when-not-to-use alternatives or exclusions, so it stops short of a 5.

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