ad_manager_fb_get_custom_audience_by_id

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds no behavioral details beyond the basic 'Get' action, such as error handling, response format, or permission requirements. It is consistent with annotations but contributes nothing extra.

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 extremely concise and front-loaded, with zero wasted words. However, it is so terse that it essentially restates the tool name without adding substantive information, which is acceptable but not exemplary.

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 read operation with annotations covering safety and schema covering parameters, the description is minimally adequate. However, there is no output schema or description of return values, error conditions, or edge cases, leaving some ambiguity for agents.

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%, with clear descriptions for audienceId and locationId (including default). The description's mention of 'by ID' aligns with audienceId but provides no additional meaning beyond the schema. Baseline 3 applies due to full schema coverage.

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 function: retrieving a custom audience by ID, which is a specific verb and resource. However, it does not differentiate from sibling tools like ad_manager_fb_get_custom_audiences (list) or ad_manager_google_get_audience_by_id, relying on the name for that distinction.

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 such as listing all custom audiences or using Google's audience retrieval. There is no mention of prerequisites, typical scenarios, or exclusions.

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