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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered; the description still adds real value by disclosing the cascade side effect (in-flight transfers are cancelled) and the 404 semantics. That cascade behavior is not inferable from the schema or annotations, making it genuinely additive. It omits any permission/auth requirement, which keeps it off 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?

Two short sentences with no filler: the destructive scope and cascade effect come first, the error case last. Nothing is repeated from the title or annotations.

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 one-parameter destructive mutation with annotations covering safety and idempotency, the description supplies the two things structured fields cannot: the cascade cancellation and the 404 outcome. The only shortfall is that the sole parameter is never described, which matters given 0% schema coverage.

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?

There is one required parameter with 0% schema description coverage, so the description must carry the burden of explaining sync_id. It only refers to the target obliquely ("её" / "её ещё идущие переносы"), adding a hint that the ID also scopes running transfers but not its type or where to obtain it. With a single scalar integer parameter this is a modest gap rather than a blocking one.

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 and resource: permanently delete a scheduled sync ("Удалить синхронизацию навсегда") and cancel its in-flight transfers. The resource maps cleanly onto the sibling naming family (create_scheduled_sync, list_scheduled_syncs, update_scheduled_sync), so an agent can distinguish it from delete_file or cancel_transfer without opening a schema. It stops short of explicitly naming a sibling it is not.

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: the permanence and cascade cancellation signal this is the hard-removal path, but the description never says when to prefer it over update_scheduled_sync (modify) or cancel_transfer (stop one transfer). No prerequisites or exclusions are stated, leaving the agent to infer the decision rule.

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