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

Goes well beyond the readOnlyHint annotation by explaining which keys are omitted under which conditions, when engagementRate is null, and how the top-5 leaderboards are ranked and truncated. It stops short of defining what engagementRate actually measures or what the count fields are.

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 purpose sentence is front-loaded and the return-value notes follow in a logical order (summary keys, then engagementRate, then leaderboards). The middle sentence about the NDA milestone is dense and takes effort to parse, but every clause conveys real conditional behavior.

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?

With no output schema, the description properly carries the return-shape burden and documents key omission and null rules that would otherwise be surprising. It is incomplete on engagementRate's definition and on what funnel count fields exist, leaving the agent to discover the full key set.

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?

A single productId parameter with 100% schema coverage that already points to listProducts for valid IDs. The description adds no further meaning about the parameter, so the baseline applies.

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?

States a specific verb and resource plus the exact contents returned: funnel counts, engagement rate, and top-tester leaderboards in one response. It is distinguishable from getTesterFunnelDetail only by implication ('in a single response', leaderboards), and never names the sibling.

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?

Use is only implied — an aggregated summary for a beta project — with no explicit when-to-use or when-not-to-use guidance. The sibling getTesterFunnelDetail is the obvious alternative for per-tester breakdowns, but the description never routes the agent to it.

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