wafle_ads_audience_overlap_check

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

Annotations declare readOnlyHint and idempotentHint, so the read-only nature is already known. The description adds important behavioral context: Meta's API is sampled and stale by hours, results are cached for 6 hours per tuple, and the matrix auto-picks audiences based on min_size. This goes beyond annotations and helps set expectations.

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 sentences plus a note, front-loaded with purpose and output. Every sentence adds value: output definition, when to use, parameter behavior, and data freshness caveat. No filler or repetition of schema details.

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?

Given no output schema, the description fully covers the return shape, input semantics, sampling/caching behavior, and a practical interpretation. It is a complete enough description for an AI agent to effectively select and invoke the tool.

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 already provides descriptions for all three parameters (100% coverage), so baseline is 3. The description adds semantic value by explaining that omitting audience_ids triggers auto-picking of audiences above min_size, and that audience_ids can 'limit the matrix'. This clarifies the relationship between parameters better than the schema alone.

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?

Description begins with a specific verb and resource ('Compute % overlap between custom audiences') and clearly states the output (matrix of overlap_pct + overlap_users). It is distinct from sibling tools like wafle_ads_compare_periods or wafle_ads_breakdown_by_creative, which focus on other ad metrics.

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?

Explicitly says 'Use this when the merchant runs many similar adsets' and provides a threshold (>40%) with interpretation. It also explains when to pass specific audience_ids versus omit them. It does not name alternative tools, but the use-case guidance is clear.

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