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

Beyond the readOnlyHint=false annotation, the description discloses that delivery history is preserved (so this is a safe reconfiguration, not a data reset) and enumerates real constraints: the bot must be admin, the target cannot be the route's source, cannot already be the destination of another route from the same source, and a VK community wall only qualifies when wall posting is open. This is material behavior an agent could not infer from the annotations or schema.

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 the effect and side effects, then the constraints, then the boundary statement — a sensible order with no filler sentences. Minor blemish: a stray ',;' punctuation and a slightly dense constraint clause that could be a bulleted list.

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 two-parameter mutation with no output schema, the description covers what changes, what is preserved, what is untouched, and which targets are valid — enough to call it correctly. It does not state what happens to already-queued or in-flight copies at the moment of the switch, a small remaining gap.

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 coverage is 100%, so both parameters are already documented and the baseline is 3. The description adds meaning on top: it points to routes.list as the source of routeId and restates the target-chat eligibility rules more fully than the schema does, including the 'already used by another route' exclusion that is absent from the schema text.

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 clause names a precise verb and resource: 'Меняет чат-приёмник маршрута' (changes the route's destination chat), and it immediately scopes the effect ('копии пойдут в другой чат'). The closing sentence 'Источник маршрута не меняется' explicitly separates it from source-level changes, so an agent can distinguish it from the many route_set_* siblings without opening a 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 a clear when-to-use context (redirect a route's copies) plus eligibility conditions for the new target. It also points to an alternative path — 'для другого источника создают новый маршрут' — implicitly routing to route_create, though it does not name the sibling tool explicitly.

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