campaign_ab_report

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

Annotations already mark this as read-only and open-world. The description adds a meaningful behavioral caveat, 'Rate limited: 2/min', and clarifies that results are split by variation. This supplements the annotations without contradicting them.

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?

Two focused sentences: the first states the tool's purpose and distinguishing behavior, the second discloses a critical rate limit. No unnecessary words 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?

For a read-only reporting tool with high schema coverage, the description is largely complete: it names the resource, explains the A/B split behavior, and warns about throttling. It does not describe the response structure, but the absence of an output schema and the straightforward 'metrics' nature make this a minor gap.

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 88%, so parameters are largely self-documenting. The description does not add parameter-level detail, and none is needed beyond the schema. It provides only domain context about A/B arms, which keeps this at the baseline.

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 states a specific verb ('Get'), a concrete resource ('per-variation email/SMS campaign metrics'), and the A/B arm scope. The phrase 'Splits results by variation so you can compare arms' clearly differentiates this from aggregate campaign report tools in the sibling list.

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 gives clear context: use this when you need per-variation A/B arm comparison rather than overall campaign metrics. It does not explicitly name an alternative or state when not to use it, but 'so you can compare arms' communicates the intended use case well.

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