Add or remove audience users

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

Annotations already disclose readOnly=false, destructive=false, openWorld=true. The description adds genuinely useful behavioral context not in the annotations or schema: input values must be SHA-256 hashes of normalized (lowercased, trimmed) emails or mobile ad IDs, and a 2500-row cap per call. It stops short of describing auth needs or the effect on existing audience members.

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 short sentences, front-loaded with the core action, then the format constraint, then the row limit. No filler; every sentence carries a constraint the agent needs.

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 mutation tool with no output schema and fully nested parameters, the description covers the data format and volume limit but omits how audience_id is sourced and what the response returns (success/failure, counts). Adequate to invoke but not complete.

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 0% and the description never mentions audience_id, so that parameter is undocumented in both places. It does compensate for the nested data payload by explaining the hash format of user_data values, but the required column_order and action_type fields are left to the enum in the schema.

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?

States a specific verb pair (add/remove) and resource (users in a custom audience), making it instantly distinguishable from siblings like create_custom_audience or update_custom_audience. An agent can tell what this does without opening the schema.

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 add/remove intent is implied by the title and description, but there is no explicit statement of when to use this versus alternatives such as reddit_ads_update_custom_audience or the list/get audience tools, nor any prerequisites (e.g. audience must be a customer list type). Usage is inferable but not guided.

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