list_playback_states

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

With no annotations, the description carries the behavioral burden. It does disclose a meaningful trait—snapshots come from the local sidecar—and 'List' implies a read-only operation. However, it does not address sidecar availability, ordering, or what happens when no snapshots exist.

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?

One sentence with no wasted words; the resource is named immediately and the source qualifier is front-loaded. It is appropriately sized for a simple read/list tool.

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 adequate for recognizing the tool but leaves gaps: no output schema means the returned snapshot fields are undefined, and no mention is made of ordering or sidecar-specific behavior. For a tool with one optional format parameter, this is acceptable but not complete.

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 single optional parameter is fully documented in the schema, including each enum value and its meaning. The description adds no parameter-specific detail, but the 100% schema coverage makes that unnecessary.

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 names a specific action ('List'), a clear resource ('saved playback state snapshots'), and a data source ('local sidecar'). This differentiates it from sibling tools like list_playlist_snapshots and list_playback_bookmarks.

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?

No guidance is given for when to choose this tool over alternatives, nor does it mention related restore/checkpoint flows. Despite many snapshot-related siblings, the description only states what the operation is, not when to use it.

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