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

Annotations already state readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds only the REST endpoint path, which hints at account scoping but does not explain pagination, filtering behavior, or result size; the extra sentence barely adds value beyond structured data.

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 description is very short and front-loads the purpose. The endpoint path is somewhat redundant but not harmful, and there is no filler prose.

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?

For a three-parameter, read-only list tool with full schema coverage and annotations, the description is minimally adequate. However, it does not mention account scoping requirements, pagination behavior, or what fields a discount record contains, leaving notable gaps for an agent invoking it.

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%, with each of the three optional parameters clearly documented in the schema itself. The description adds no parameter detail, so the baseline score of 3 applies when the schema does all the work.

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 gives a clear verb and resource ('List configured discounts'), so an agent knows exactly what is returned. It does not, however, differentiate this from sibling list tools such as tillhub_list_products or tillhub_list_taxes beyond the resource name.

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?

There is no guidance on when to use this tool versus alternatives, no prerequisites, and no mention of pagination strategy despite the next_query parameter. The agent is left to infer everything from the name.

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