Get X Pixel

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

The annotations already declare readOnlyHint=true and openWorldHint=true, so the description doesn't need to cover safety. The description adds the list of returned fields (type, windows, retargeting, embed_code, website_tag_id), which gives context about the output. No contradictions or missing behavioral caveats beyond what annotations provide.

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 a single concise sentence that front-loads the primary action ('Fetch one web event tag') and then lists the returned fields. There is zero fluff and every word earns its place.

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 simple get tool with only two parameters and no output schema, the description is mostly sufficient. It lists what the response contains, but it omits important context about the web_event_tag_id parameter – specifically where it comes from (e.g., list_pixels). The account_id parameter is sourced in the schema, but the tag ID is not. This is a minor gap that could confuse an agent on first 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?

Schema coverage is only 50% – account_id is described in the schema, but web_event_tag_id has no description. The description does not add meaning to the parameters; it only lists fields that appear to be part of the response, not the input. It fails to clarify that web_event_tag_id likely refers to an existing pixel ID from list_pixels. Since coverage is not high, the description should compensate but doesn't.

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 ('Fetch'), a specific resource ('one web event tag'), and lists the fields returned. This clearly distinguishes it from sibling tools like x_ads_list_pixels (which lists all pixels) and x_ads_delete_pixel (which deletes). An agent can immediately understand what this 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?

No guidance is provided on when to use this tool versus alternatives. It doesn't mention that list_pixels should be used to get all pixels, or that this is the singular getter. The only clue is the sibling names, but the description doesn't explicitly route the agent.

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