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

Annotations already cover readOnly, idempotent, and non-destructive hints, so the description's added value is return structure: it discloses the blended vs per-plan-tier segmentation and the derived nature of the CAC target. It also adds the Stripe-connectivity dependency, which annotations do not convey.

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 each carry distinct value: what is returned, the segmentation detail, and when/how to use it. Content is front-loaded and there is no filler or repetition of annotation info.

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 does a good job of conveying return contents (including segment-specific LTV/CAC targets) and preconditions. Minor gaps remain around exact response shape or metric units, but the tool can be selected and invoked correctly from this description alone.

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% and companyId is already fully described with membership and scoping context. The description adds no parameter-specific details, but none are needed; baseline 3 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?

The description names the exact resource ('Stripe metrics') and enumerates the specific metrics returned (LTV, MRR, churn, active subscriptions, CAC target), making it immediately clear what the tool does. It also differentiates from siblings like get_cac_strategy and get_subscription_stats by specifying both blended and per-plan-tier segments.

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?

It states an explicit use case ('guide customer acquisition spend decisions per customer type') and a hard prerequisite ('Only works if Stripe is connected'). It references related tools (get_cac_strategy / set_cac_strategy) for the strategy context, though it does not explicitly name alternative tools or state when not to use this one.

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