agent_list

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

Annotations declare readOnlyHint=true, and the description's 'Read' aligns with a safe read operation. It adds context beyond annotations by enumerating the specific data returned (identity, active-room reference, connection status), which helps the agent understand expected output. No contradictions.

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?

Three sentences, each serving a purpose: the first defines the action, the second gives a usage trigger, the third names an alternative. No unnecessary information, appropriately sized and front-loaded.

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?

With an output schema present and a read-only annotation, the description covers the tool's purpose, usage timing, and relationship to alternatives. It is complete for a zero-parameter read operation, requiring no further explanation of return values.

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 are zero parameters, so schema coverage is 100% and the description does not need to explain parameter meanings. The baseline for zero-parameter tools is 4, and no additional parameter information is necessary.

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 states a specific verb ('Read'), a specific resource ('this local agent's identity, active-room reference, and connection status'), and clearly distinguishes it from sibling tools like room_info by focusing on local agent state rather than room state. This is unambiguous and differentiates from 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 provides when to use: 'Use after agent_register to confirm local identity or when no active room is available.' It also names an alternative tool: 'Use room_info instead for detailed state of a currently joined room.' This offers clear selection guidance.

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