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

readOnlyHint=true already establishes the safe-read profile, so the description's added value is the shape of the result: newest-first ordering, cursor pagination, and the per-row fields points_change (+/-), customer-visible description and merchant internal_note. That internal_note/customer-visible distinction is genuinely useful behavioral context an agent would not get from annotations alone. No permission or rate-limit detail is given.

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 compact sentences, front-loaded with the resource and scope, then the record shape, then pagination and the API endpoint. Every clause carries information; nothing is padding.

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 dutifully characterizes the returned rows and their ordering and paging behavior, which is the main gap an agent would otherwise face. It leaves the filtering semantics of customer_id and updated_at_min to the schema, which is acceptable at 100% schema coverage.

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 limit, cursor, customer_id and updated_at_min are already fully documented. The description only reinforces the cursor concept via 'Cursor-paginated' and implies customer scoping, adding no syntax or constraint detail beyond the schema. 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?

States a specific verb and resource ('List points transactions') and immediately enumerates the scope of what is listed (every earn, spend and manual adjustment). Ordering (newest first) and a concrete use case (a customer's full points history) make it trivially distinguishable from the singular smile_get_points_transaction and from smile_create_points_transaction.

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 example 'a customer's full points history' tells the agent the context in which this tool is the right choice, and 'Cursor-paginated' plus 'Omit for the first page' frames the paging workflow. It never explicitly excludes itself in favor of the sibling fetch-one tool, so it stops short of full when/when-not guidance.

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