who_is_online

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool shows currently connected members, implying a real-time or snapshot view, but does not disclose whether authentication is required, how 'connected' is defined, whether the list is ordered, or what happens if no one is online. It also doesn't mention any limitations (e.g., staleness, permissions). This is a minimal disclosure for a read-only presence tool.

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 a single, concise sentence that directly states the purpose. It is front-loaded with the action and object, containing no filler or redundancy. It earns a high score for brevity and clarity.

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?

Given the simplicity of the tool (no parameters, no output schema), the description is nearly sufficient, but it leaves the return format unspecified. It does not state whether the result is a list of names, a count, or a structured object. The description implies the output lists connected members but doesn't confirm it. For a presence tool, this ambiguity is a minor but notable gap.

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 has zero parameters, and the schema has 100% coverage (trivially). With no parameters to document, the description does not need to explain parameter semantics. The baseline of 4 for zero parameters is appropriate; the description adds no parameter-related meaning because none exists, and that is acceptable.

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: to see which team members are currently connected. It uses a specific verb ('see') and resource ('team members'), and the meaning is distinct from siblings like list_members (which likely lists all members regardless of presence) and check_lock (which checks lock status). While it doesn't explicitly name a sibling, the purpose is unambiguous and informative.

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 provides no guidance on when to use this tool versus alternatives such as list_members or other presence-related tools. It does not state any conditions, exclusions, or mention of when this tool is preferred. The usage context is implied (checking online status) but not made explicit.

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