Lists all running ROS 2 node names to verify if a node is alive and inspect what is active in the system. Returns node count and names.
列出当前 ROS2 系统中所有正在运行的节点名。
何时用：确认某个节点是否活着；排查前先看看系统里有什么。 返回：node_count 与 nodes 列表（全名以 / 开头）。 nodes 为空说明未发现任何节点——系统未启动、与本机 ROS_DOMAIN_ID 不同或 daemon 异常，可用 health_check 进一步检查。 失败时返回 error 字段。
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden and does well: it states the return fields node_count and nodes, explains that empty nodes means no nodes were discovered, lists likely causes, and notes the error field on failure. It does not explicitly state that the operation is read-only or discuss performance/rate characteristics, but for a zero-parameter listing tool this is minor.
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?
Front-loads the purpose, then follows with when-to-use, return shape, empty-result interpretation, and failure behavior. Every sentence adds useful operational context without wasted words.
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?
There is no output schema, so the description must explain return values, which it does by naming node_count and nodes and describing their format. It also covers the empty and error cases, making the definition complete for this simple inspection tool.
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 tool takes no parameters, so the baseline is 4. The description correctly does not invent parameter documentation, and the empty schema needs no further semantic explanation.
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?
Stated as a specific verb and resource: lists all currently running ROS2 node names. The scope (current ROS2 system, all running nodes) clearly separates it from get_node_info, list_topics, and other siblings.
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?
Explicitly says when to use it: to confirm whether a node is alive and to survey the system before troubleshooting. It also names health_check as the follow-up when no nodes are found, though it does not compare against all sibling diagnostics tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.