z2m_permit_join

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

The description discloses an important side effect beyond the annotations: 'While open, any nearby Zigbee device may join, so keep the window short.' This adds behavioral context not captured by readOnlyHint or destructiveHint. It also explains how to close the network and the purpose of router scoping, plus the idempotent nature of the time parameter.

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 three sentences long, front-loaded with the core action, followed by a safety warning and a pointer to an alternative. Every sentence earns its place with no redundancy. It is concise and well-structured.

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?

The description is complete for the tool's complexity: it covers what it does, when to use it, safety considerations, how to close it, optional scoping, and how to check current state. With no output schema, the description compensates by providing all necessary context. The schema fills in parameter specifics.

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 input schema already provides full descriptions for both parameters (time and device). The description elaborates further by advising to use 0 to close, and by recommending router scoping as 'the recommended way to pair a device into a specific part of the mesh.' This adds contextual meaning beyond the schema, though the schema already covers the basics.

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 tool's purpose: 'Open or close the network for new devices to join.' It uses a specific verb and resource, and distinguishes itself from sibling tools like z2m_bridge_info (which checks status) and device-specific tools. The mention of scoping to a single router adds clarity.

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 description explicitly tells when to use the tool ('Open or close the network'), gives best practices ('keep the window short and close it with time=0 when finished'), and names an alternative for checking state ('Use z2m_bridge_info to see whether joining is currently open'). This provides clear guidance on both usage and alternatives.

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