Lists physical sub-devices connected locally behind a master device, using its public ID. Returns empty until the master reports one; software agents are excluded.
List the physical sub-devices connected locally behind this device, if it's acting as a master. Empty until the master actually reports one, this never includes software agents.
| Name | Required | Description | Default |
|---|---|---|---|
| deviceId | Yes | The master device's public id. |
Changes observed during successful MCP inspections.
v0.1.5Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and does useful work: it discloses that results are conditional on the master role, will be empty until the master reports a sub-device, and never includes software agents. It does not mention auth requirements or pagination, but the key behavioral traits are surfaced.
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?
A single tight sentence front-loads the operation and scope, with the role condition and exclusion clause appended without waste. Nothing could be removed without losing information.
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 one-parameter read-only listing with no output schema, the description covers the salient edge cases (empty until reported, no software agents) and the master-role precondition. Auth/permission context is missing but not critical for a list operation.
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?
There is one parameter (deviceId) with 100% schema description coverage, so the schema already documents it fully. The description notes the master-role context that makes deviceId meaningful but adds no syntax or format detail beyond the schema. Baseline 3 applies.
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?
States a specific verb (List) and resource (physical sub-devices connected locally behind this device), plus the role condition (acting as a master). It also carves out what it does NOT return (software agents), which helps distinguish it from list_devices, though it never names a sibling tool explicitly.
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 phrase "if it's acting as a master" implies when the tool is applicable and that it may return nothing otherwise. However, it gives no explicit when-to-use/when-not guidance relative to alternatives like get_sub_device or list_devices, leaving the agent to infer routing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.