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

Annotations already declare this a safe read (readOnlyHint=true, destructiveHint=false), so the bar is lower. The description adds genuinely non-structured context: the shape of the returned funnel hierarchy and the auth prerequisite ('needs the user's Cotlet API key with access to this app'), which is exactly the kind of operational detail annotations cannot 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 short sentences, front-loaded with what is returned. The first and second sentences partially overlap (both enumerate pricing options, bumps, upsells, downsells), which is mild repetition but not wasteful enough to hurt usability.

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 takes on the job of explaining the return payload, and it does so reasonably: product, pricing options, and funnel items with IDs and prices. Combined with the stated auth requirement and single documented parameter, an agent has enough to call this correctly.

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?

There is a single parameter with 100% schema description coverage, so the schema already carries the meaning; baseline is 3. The description only implies the parameter indirectly via the coupon/affiliate use case and duplicates the schema's hint that the ID comes from list_products.

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 states a specific resource and scope: a single product plus its pricing options, bumps, upsells and downsells, with each funnel item carrying its own ID and price. It implicitly contrasts with the singular-vs-list sibling list_products by saying 'One product', though it never names that sibling explicitly.

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 gives a concrete use case ('Use it to pick the product_ids for a coupon or an affiliate'), which tells the agent when this call is the right choice. There is no explicit when-not guidance or naming of an alternative such as list_products when the product is unknown.

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