Capture a snapshot of the current Spotify playback state and store it in a named local slot for later retrieval or analysis.
Snapshot current playback state to a named local slot (sidecar JSON).
| Name | Required | Description | Default |
|---|---|---|---|
| name | No | Slot name (default: timestamp) | |
| response_format | No | 'concise' = human prose, 'detailed' = more fields in prose, 'json' = raw API object | concise |
Changes observed during successful MCP inspections.
v1.26.1Does 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 does reveal the persistence mechanism (local sidecar JSON) and that this is a mutating write, but it omits key traits: whether an existing slot with the same name is overwritten, what 'playback state' includes (context, queue, device, position?), whether active playback is required as a precondition, and what happens on failure.
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 nine-word sentence that front-loads the action and includes the two most decision-relevant facts: the destination ('named local slot') and the format ('sidecar JSON'). Every word earns its place with zero waste.
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 tool with only two optional, fully documented parameters and no output schema, the description is minimally adequate: it tells the agent what action to take and where the result goes. However, it lacks usage context among many similar siblings and does not clarify edge behavior (overwrite, empty state, inclusivity of the snapshot), leaving an agent to guess.
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?
Schema description coverage is 100%, so both parameters (name, response_format) are already fully documented in the schema. The description adds only marginal value by linking 'named' to the name parameter and 'sidecar JSON' to the JSON storage format, so the baseline 3 applies.
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 ('Snapshot'), a clear resource ('current playback state'), and a destination ('named local slot (sidecar JSON)'). This is unambiguous about what the tool does, but it does not explicitly differentiate itself from closely related siblings like capture_playback_position, checkpoint_playback, get_playback_snapshot, or save_scene.
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 provided on when to use this tool versus alternatives. With roughly a dozen overlapping snapshot/save/capture tools among siblings (checkpoint_playback, capture_playback_position, save_scene, taste_checkpoint, get_playback_snapshot), an agent has no basis to choose between them, and no exclusion conditions are stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.