multi_account_summary

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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds valuable behavioral context by disclosing the 2/min per-account rate limit and the potentially long runtime across many accounts, which is important for an agent deciding whether to call this tool.

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 convey the tool's purpose, scope, output, and the key operational constraint (rate limit/runtime) with no filler. The most important information is front-loaded.

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?

The description explains purpose, scope, and a critical rate-limit behavior, and the schema covers parameter semantics. It does not describe the exact fields in the unified report, which is a minor gap given no output schema exists, but the description is still sufficient for correct invocation.

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 the schema fully documents all six parameters, including the important conversion_metric_ids caveat. The tool description itself adds no parameter-specific meaning, which is acceptable given the schema already 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?

Description states a specific verb ('Pull'), a specific resource ('ALL configured Klaviyo accounts'), and the output ('campaign performance summary' / 'unified cross-brand report'). This clearly distinguishes it from single-account sibling report tools.

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 makes clear this is for cross-account, cross-brand summary needs, which implies it is the right choice when aggregating across all accounts. It does not explicitly name alternative tools or say when not to use it, but the 'ALL configured accounts' framing provides clear contextual guidance.

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