bb_run_actionTrigger any Blockbench action by its BarItems id to execute built-in UI commands programmatically. Use bb_list_actions to find valid ids.
Trigger any Blockbench action by its BarItems id (see bb_list_actions). This reaches every built-in command the UI exposes.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes |
Changes observed during successful MCP inspections.
v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden, and it does not say what happens on an invalid id, whether triggered actions are undoable, or that these commands may mutate/destroy project state. 'Reaches every built-in command the UI exposes' hints at broad, potentially destructive scope but stops short of warning about it.
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, zero waste, with the essential mechanic (id-driven dispatch) front-loaded before the scope note.
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 an unannotated, output-schema-less dispatcher that can invoke any UI command, the description omits error behavior, undo/reversibility, and side-effect expectations. The agent has enough to attempt a call but not enough to anticipate its consequences.
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% for the single 'id' parameter, so the description must compensate. It does explain that the value is a BarItems id obtainable via bb_list_actions, but adds no format, casing, or example beyond that. Partial compensation only.
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?
Specific verb ('Trigger') plus resource ('any Blockbench action') and it names the mechanism (BarItems id). It also routes to bb_list_actions, cleanly separating the enumeration tool from the execution tool.
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 parenthetical '(see bb_list_actions)' tells the agent where to get a valid id, which is useful context. But there is no guidance on when to prefer this over bb_execute_js, nor any exclusions or preconditions for the call.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.