Registers an RPC service on the private message bus for a specified EDA window, enabling remote procedure calls within the design environment.
sys_MessageBus.rpcService(topic: string, callbackFn: (...args: Array) => any | Promise) -> void 私有消息总线：注册 RPC 服务
| Name | Required | Description | Default |
|---|---|---|---|
| args | No | 按官方签名顺序排列的JSON参数数组 | |
| windowId | No | 目标EDA窗口ID；省略时使用当前活动窗口 |
Changes observed during successful MCP inspections.
v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It only notes that it's a private message bus, implying scope, but does not explain the side effects of registration, whether it can be overwritten, what the callback receives, or any other behavioral nuances. This is insufficient for an AI to understand the operation's impact.
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?
The description is very brief (two lines), which is concise, but it lacks structured explanation. It front-loads the signature but does not organize the information in a way that aids understanding. The terseness borders on under-specification.
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 tool that registers an RPC service, the description should explain the topic parameter, the expected callback behavior, and how it relates to other message bus operations. None of this is provided. With no output schema, it also fails to describe the return value beyond the void signature. The description is inadequate for proper usage.
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?
The schema has 100% coverage for its two parameters (args and windowId). The description does not add meaning beyond the schema; it only provides a low-level signature. Since the schema already explains that args is a JSON array in official signature order, the description adds no extra value, so a 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 clearly states the action: 'register RPC service' (注册 RPC 服务) on a private message bus, which is a specific verb+resource. It distinguishes itself from sibling message bus tools by indicating it is for registering a service, though it doesn't explicitly name alternatives.
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?
No guidance is provided on when to use this tool versus other message bus operations (e.g., publish, subscribe, rpc_call). The description does not mention any conditions, exclusions, or alternative tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.