ad_manager_fb_add_custom_audience_member

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

Annotations already indicate readOnlyHint=false, idempotentHint=true, and destructiveHint=false. The description adds nothing beyond the bare action – no mention of side effects, idempotency implications, or what happens if a member already exists. It fails to disclose any behavioral traits beyond what the annotations already 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 sentence with no waste, but it essentially restates the tool name with minimal added value. It is not front-loaded with any useful context beyond the action itself, so while concise, it is not particularly informative.

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 write operation with 4 parameters and no output schema, this description is incomplete. It does not explain return values, error conditions, or edge cases like duplicate members. An agent requires more context to call this tool correctly.

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% for all 4 parameters, so the schema already documents each field. The description adds no extra meaning about parameter semantics, relationships, or usage details. This is the baseline 3 because the schema carries the burden.

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 the action: 'Add custom audience member' – a specific verb and resource. However, it does not differentiate from sibling tools like ad_manager_fb_remove_custom_audience_member or ad_manager_fb_batch_update_audience_members, so it misses the distinction that would make it a 5.

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. There is no mention of prerequisites, exclusions, or context like 'use batch update for multiple members'. The description offers no usage direction at all.

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