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

Annotations already declare openWorldHint=true and idempotentHint=false, so the description's added value is elsewhere: it discloses tool_use support, the multi-account routing behavior implied by account_email/account_tag forcing, and the return shape including a tool_calls branch. It does not describe failure modes (what happens if a forced account is exhausted) or latency/cost behavior, which would have earned a 5.

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 front-loaded with a one-line summary followed by cleanly separated Args/Returns blocks, which is exactly the structure an agent needs for a chat-completion call. The only wasted token is the ambiguous '(high)' qualifier, which is never explained.

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 Returns section does the necessary work by specifying {"text", "usage"} and the tool_calls variant, and the Args block covers every one of the six parameters at 0% schema coverage. For a stateless chat-inference call whose annotations already cover the safety profile, nothing essential to 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 description coverage is 0%, so the description must carry the full parameter burden, and it documents all six: messages structure, system prompt, max_tokens, Anthropic-format tools, and the two account-forcing parameters. The gaps are depth — 'content: "..."' is not formalized, and it never says what happens if both account_email and account_tag are supplied, nor that max_tokens defaults to 32000.

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 first line names a concrete verb and resource ('Запрос к Claude Sonnet 5.5') and positions it against a named alternative ('быстрее Opus 5.5'). It also flags the distinguishing capability (tool_use support), so an agent can tell what class of tool this is without opening the schema. It stops short of naming the actual sibling tool (e.g. chat_claude_opus) that would be the routing alternative.

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 only usage signal is the comparative 'faster than Opus 5.5', which implies a speed/quality trade-off but never states when to pick this over chat_claude_opus, chat_claude_sonnet, or the Gemini siblings. There are no explicit exclusions or prerequisites (e.g. credit requirements, account availability), so the agent must infer selection criteria.

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