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

With no annotations, the description carries the full behavioral burden, and it does disclose one genuinely useful trait: the 5-minute activity window, which tells the agent how fresh the data is. It says nothing about auth requirements, whether the caller appears in the list, ordering, or response shape.

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 fragment with zero padding, and the key qualifier (last 5 minutes) is front-loaded. It is minimal rather than wasteful, though the missing verb keeps it from being a model of structure.

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 zero-parameter read tool with no output schema, the description covers the core semantics but omits the return shape (list of agent identifiers? objects?) and any prerequisite like authentication or team membership. Adequate but with visible gaps.

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 zero parameters, so the baseline of 4 applies. There is nothing for the description to add on this dimension.

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 what the tool returns (agents active in the last 5 minutes), which is a meaningful resource + scope, but it is a noun fragment with no verb and no differentiation from siblings like get_activity, get_team, or me. An agent can infer the resource but must guess the operation framing.

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?

There is no guidance on when to use this versus get_activity, get_team, me, or heartbeat, all of which touch overlapping 'who is around' territory. Usage is only implied by the presence concept.

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