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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds genuinely useful behavior beyond that: only *enabled* rules are returned, the response carries reward/reward_value/earning_limit and VIP-tier restrictions, and results are cursor-paginated. This is meaningful added context for a read 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 compact, front-loaded sentences: purpose and explanation first, then returned fields, then pagination and the underlying Smile endpoint. The parenthetical examples of earning types earn their place by making the resource concrete; nothing is wasted, though the field enumeration borders on redundant detail.

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 compensates well by naming the key returned fields (reward, reward_value, earning_limit, VIP-tier restriction) and the pagination model. An agent can call this correctly with just the schema plus description; only the full response shape and permission requirements remain unstated.

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% — both 'limit' (1-250, default 50) and 'cursor' are fully documented in the schema, so the baseline is 3. The description only restates pagination ('Cursor-paginated') without adding format or edge-case detail beyond the schema.

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 the enabled earning rules') and explains what the resource actually is ('the ways customers earn points or rewards'), which is more than a restatement of the name. It does not explicitly differentiate itself from any sibling, though the sibling set is composed of unrelated resources, so confusion risk is low.

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?

Usage is only implied: 'Cursor-paginated' hints at the multi-page retrieval pattern, and 'enabled' implies a filter over the full rule set. There is no explicit when-to-use guidance, no mention of prerequisites (e.g., API credentials), and no named alternative for retrieving disabled rules or a single rule.

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