create_instance

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

There are no annotations, so the description carries the full behavioral burden. It discloses the mutation ('размещает на холсте') and adds a genuinely useful capability boundary against write_node, but it says nothing about failure behavior (missing or stale componentKey), whether the underlying component must be published, or whether the operation is idempotent beyond the operationId note that already lives in the 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?

Two tight sentences: the primary action and its two modes come first, followed by the sibling disambiguation. Every clause carries information an agent needs, with no filler or repetition of schema content.

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 7-parameter, zero-required mutation tool with no annotations and no output schema, the definition leaves real gaps. Most importantly it never states what is returned (presumably the new instance node id, which downstream tools like move_node or update_node would need), and it does not resolve the ambiguity of an all-optional parameter set.

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 57%, so the description must compensate for the undocumented parameters. It does add the key semantic that componentKey and componentNodeId are alternative sources of the same component, which the schema alone does not convey. However, x, y and name receive no mention at all, and there is no warning that supplying neither source is invalid despite zero required parameters.

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 ('Создаёт инстанс компонента') and states the scope: it places the instance on the canvas. It also distinguishes itself from a concrete sibling ('write_node компоненты не создаёт, только FRAME/RECTANGLE/TEXT'), so an agent can separate the two without opening either 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 explains the two creation paths and ties each to a parameter: local components via componentNodeId, same-file components via componentKey from get_components. It also states an explicit non-use case (write_node). It does not address alternatives such as clone_node or when a placement/parent choice should be preferred, which keeps it short of a 5.

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