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

Beyond the annotations (readOnlyHint=false, destructiveHint=false), the description discloses substantive behavior: secret tokens are never returned or transmitted, accounts are not created or edited here, and there is no 'enable payment' toggle — payment works only when a seller account exists and the tariff permits the widget. These are exactly the constraints an agent needs before invoking.

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?

It is dense but front-loaded: purpose and action semantics come first, followed by prerequisites and exclusions. Every sentence carries information, though the prerequisite paragraph is long enough that a reader must parse several clauses before reaching the boundary conditions.

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 by describing what show returns (settings, seller accounts without secret tokens, calculation types) and by spelling out prerequisites and the absence of a toggle. Nothing an agent needs to call it correctly appears to be 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%, so the baseline is 3, but the description adds real meaning by describing the save workflow — choosing an account, a calculation type (fixed vs. points), the amount, and the question supplying the receipt contact — tying the parameters into a coherent operation rather than restating them.

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 states a specific verb+resource: accepting payment in a quiz via YooKassa, and then splits it into the two actions (show/save) with their concrete effects. It is clearly distinguishable from generic quiz tools and from update_quiz_widgets, which it explicitly names as a different concern.

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?

It explains when each action applies (show for current settings/accounts, save to configure account, calculation type, amount and receipt-contact question) and explicitly routes related work elsewhere — seller accounts require store ID and secret token and are managed in the cabinet, not through the assistant, and widget display is set via update_quiz_widgets.

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