wafle_ads_performance_summary

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

Annotations already declare readOnlyHint and idempotentHint, so the description adds valuable context beyond that: the data sources, the return fields (meta_reported_orders vs wafle_orders), and the inclusion of a prev_period block. This gives the agent a good sense of what to expect without overstating operational details.

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 compact and front-loaded. The first sentence states the purpose, the second details output metrics and usage, with no wasted words. Every sentence carries meaningful information.

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 the tool's complexity (joining two data sources, many return fields, no output schema), the description reasonably compensates by listing key metrics and the prev_period block. It could mention how days applies to both sources or define derived metrics more explicitly, but it is largely sufficient for a read-only summary 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 description coverage is 100%, so both parameters (days, slug) are fully described in the schema. The description does not add any additional parameter semantics but also does not need to; baseline of 3 is appropriate.

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 tool's function: account-level cross-tabbed performance, joining Meta marketing data with wafle CAPI orders/revenue. It also lists the specific metrics returned, distinguishing it from sibling tools like anomalies_list or compare_periods.

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 explicitly says 'Use this as the input to any optimization decision', providing clear context for when to use the tool. It does not, however, name alternatives or explicitly state when not to use it, hence a 4 rather than 5.

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