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

With readOnlyHint and openWorldHint already set, the description still earns credit for disclosing real behavioral traits: platform-dependent availability (views only on MAX, reactions only on Telegram), that missing data comes back empty rather than zero with a countedAs explanation, and that growth stays empty until the series covers the period. It does not cover pagination, limits on best-post count, or response shape beyond field names.

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?

Purpose and metric list are front-loaded, and every sentence adds information — the platform caveats, the empty-vs-zero rule, and the no-post-texts note all matter. It is a dense single block of prose, though, and the caveats could be broken out for faster scanning.

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?

There is no output schema, so the description carries the full burden of explaining return values, and it does: the metric set, the per-platform availability, the countedAs field, the empty-instead-of-zero convention, and the absence of post texts. An agent can predict and interpret the response from the description alone.

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 schema already explains that days bounds the post window to 1–30 and defaults to 7. The description adds only a mild framing ('за период', growth always 7/30/90) that duplicates the schema rather than extending it, so the baseline of 3 is appropriate.

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 names a specific verb and resource ('Показывает статистику своего канала') and then enumerates exactly what is returned: subscriber count and growth over 7/30/90 days, a daily subscriber series, post counts, average views, and top posts with their fields. The 'своего канала' scoping plus the metric list makes it clearly distinct from chatbot_stats and the rest of the sibling set.

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?

Usage is only implied — an agent wanting channel analytics naturally reaches for this tool — but the description never states when to prefer it over chatbot_stats, nor any exclusions or prerequisites. The only routing hint (chatId comes from chats.list) lives in the schema, not the description.

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