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

With annotations already declaring readOnlyHint=false, openWorldHint=true, idempotentHint=false and destructiveHint=false, the description still adds real behavioral context: email content uses made-up answers, the subject is marked «Пример», the quiz must be published, and there is a one-per-minute throttle. This is meaningful disclosure beyond the annotations, though it omits where the test message is delivered for the client case.

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?

Three compact sentences: the action first, then the sample-marking, then prerequisites and rate limit. Every sentence carries actionable information and the main verb is front-loaded. Slightly dense, but no filler.

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?

No output schema exists, but the description is complete enough for a test-send tool: it describes what the message contains, the required quiz state, and the throttle. Combined with the annotations (non-read-only, open-world side effect of actually sending mail), an agent has what it needs to call it correctly.

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%, so the enum semantics for type (owner = email about a new answer to you, client = email to the respondent) and quiz_id are already documented in the schema. The description restates the same owner/client distinction without adding syntax or format detail. Baseline 3 is appropriate when the schema does the heavy lifting.

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: sending a sample/test email rendered in its current form (subject, template, logo, sender) with faked answers. It distinguishes the two modes (owner vs client) inline, so an agent understands what the call produces. It does not explicitly name a sibling it is not, so it stops short of a 5.

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 concrete preconditions and constraints: "Нужен опубликованный опрос" (a published quiz is required) and "Не чаще раза в минуту" (at most once per minute). These tell the agent when the call is valid and its rate limit. It does not contrast the tool against an alternative (e.g., a non-test send), so not a 5.

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