Get a cash register

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds real behavioral context beyond that: what fields come back in each mode, the meaning of offline_mode, and that the open shift is included.

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 dense sentences with no filler; the core behavior is front-loaded and the conditional cases are laid out in a compact parallel structure.

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 carries the return-value burden and does enumerate the fields returned in each mode, which is adequate for a single-optional-param read tool. It stops short of describing nesting or error behavior, but nothing essential for invoking it correctly is missing.

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 coverage is 100% and the schema documents the UUID pattern, so the baseline is 3. The description goes further by explaining the semantic consequence of supplying versus omitting cash_register_id, which is genuinely more than the schema conveys.

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 ('Returns one cash register (ПРРО)') and immediately differentiates the two operating modes via the presence or absence of cash_register_id. It does not name sibling tools like list_cash_registers, so it is clear but not sibling-differentiating.

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?

Explicitly describes the two calling contexts: with cash_register_id you get full details plus the open shift; without it you get the register bound to CHECKBOX_LICENSE_KEY. It gives clear context but names no alternative tool for listing multiple registers and states no exclusions.

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