list_registers

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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered by structured data. The description adds only that results include outlet and open/closed state, which duplicates what the output schema likely conveys; it says nothing about ordering, pagination, or filtering scope.

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?

A single economical sentence with the resource and returned attributes front-loaded and zero filler. It is arguably overly terse for the amount of surrounding capability, but nothing in it wastes space.

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 parameters, full annotation coverage, and an output schema to describe return values, the description needs only to establish scope and identity, which it does. A note on ordering or whether inactive registers are included would have closed the remaining gap.

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?

The tool takes zero parameters, so the schema has nothing to explain and no semantic gap exists. Baseline 4 applies; the description adds no parameter information because none is needed.

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?

Names a specific resource (registers/tills) and states what the listing includes: outlet association and open/closed state. It is clearly distinguishable from siblings like list_outlets or list_payment_types, though it never uses an explicit verb ("List") or calls out that differentiation.

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 description gives no guidance on when to prefer this tool over siblings such as list_outlets, nor any preconditions or exclusions. The single sentence is purely descriptive of contents, leaving usage entirely to inference.

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