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

Annotations declare this is a non-idempotent, non-destructive write, and the description adds behavior the annotations cannot: rules are replaced wholesale by the list, and emails only reach confirmed addresses ('письма уходят только на подтверждённые адреса'). It does not describe the response or error behavior, which is the only remaining gap.

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 verb leads, followed by the feature enumeration and then the update/recipient/current-value caveats. The first sentence is dense and list-like but every clause carries distinct information; nothing is padding.

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 7-parameter nested mutation tool with no output schema, the description covers the feature surface, update semantics, recipient validation, and where to read current values. It omits failure modes and return behavior, but a save tool's return is not critical information.

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?

With 100% schema description coverage the baseline is 3, but the description adds semantics the schema does not: only the fields being changed should be passed, and the rules array is a full replacement (empty list deletes all rules). These are parameter-level facts an agent could not infer from the JSON schema alone.

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 opens with a precise verb and resource ('Меняет «Уведомления» опроса сверх писем') and then enumerates the exact sub-areas it governs: rules, digest, events, respondent reminder, and score flags. This scope ('сверх писем' — everything beyond the plain email template) lets an agent separate it from save_quiz_email_template or set_quiz_email_questions without opening any schema.

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 gives real operating guidance — 'Передавайте только то, что меняете' (partial update) and points to the read counterpart ('Текущие значения — поле notifications в get_quiz_email_settings'). It stops short of naming sibling tools it must not be confused with, so 5 is not warranted.

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