List players

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 disclosing behavior. 'List' and 'known to the server' make clear this is a read-only server query, and 'their state' indicates what is returned. However, it does not define what 'state' includes or whether disconnected/disababled players are listed, leaving some behavioral ambiguity.

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 sentence with no filler. The core action and scope are front-loaded, and every word adds value.

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 tool with no output schema, the description is largely sufficient: it states what is listed (players) and what is returned (state). It does not specify the return structure or fields of 'state', but an agent can still invoke the tool and inspect the response without ambiguity.

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, so schema description coverage is trivially 100%. With 0 params, the baseline is 4, and the description does not need to add parameter-level meaning. No parameter information is missing.

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 uses a specific verb ('List') and identifies the exact resource ('Squeezebox / squeezelite players known to the server') plus what is returned ('their state'). This clearly distinguishes it from sibling tools like show_queue, now_playing, and playback_control, which focus on queues, current tracks, and playback actions.

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 implies the tool is for discovering all players and their current state, which is a reasonable usage context. However, it does not explicitly state when to prefer this over sibling tools or mention any alternatives/exclusions. For a simple zero-parameter listing tool this is a minor gap rather than a serious one.

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