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

The description discloses key behaviors: created PAUSED, WRITES live, and accepts three creative sources. This adds value over annotations (only readOnlyHint false) by specifying state and write impact. However, it does not cover error handling or behavior with conflicting inputs.

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?

Two sentences, front-loaded with action and key constraints (paused, write live, creative options). Every sentence adds essential information without redundancy.

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?

Despite covering purpose and creative options, the description omits details on most parameters, return values (e.g., ad ID), prerequisites (e.g., adset must exist), and potential errors. For a tool with 11 parameters and no output schema, this is insufficient.

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 only 27% (3 of 11 parameters described). The description mentions three ways to provide creative but does not explain the other 8 parameters (ad_name, page_id, etc.). It groups 'ad copy fields' vaguely without mapping to schema properties, leaving significant gaps.

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 it adds a new ad to an existing ad set, specifies it is created paused, and lists creative options. The verb 'add', resource 'ad to adset', and scope are precise, distinguishing it from bulk operations.

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 context (add single ad to existing ad set) but does not explicitly compare to alternatives like bulk creation tools, nor provides when-not guidance. The sibling list contains no direct equivalent, so implicit use is clear but not formally guided.

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