Adds a plugin instance to a device playlist via TRMNL API so you can assign which plugin appears on a specific device. Use it to update playlists remotely.
Add a plugin instance to a device playlist TRMNL POST /api/devices/{device_id}/playlist_items. Changes remote state or starts work. Run only within the user-authorized scope.
| Name | Required | Description | Default |
|---|---|---|---|
| body | Yes | ||
| path | Yes | ||
| profile | No | Configured profile name; defaults to default. |
Changes observed during successful MCP inspections.
v0.2.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false and destructiveHint=false, so the agent knows this is a non-destructive mutation. The description adds that it 'changes remote state or starts work' and requires authorized scope, which is useful but vague. It does not explain the practical consequence of idempotentHint=false, such as whether repeated calls create duplicate playlist items.
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 short and front-loads the action and endpoint. 'Changes remote state or starts work' is slightly generic boilerplate, but overall there is little 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 mutation tool with a nested body and no output schema, the definition covers the basic action, endpoint, and authorization scope. It leaves important behavior gaps: whether the item is appended at the end, whether duplicates are allowed, and how the playlist order is affected.
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 only 33%, and the description does not compensate by explaining what plugin_setting_id, device_id, or profile mean in this operation. The prose implies a plugin instance and a device, but adds no real semantics beyond the parameter names and schema.
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 and resource: add a plugin instance to a device playlist, and names the underlying POST endpoint. It is clearly distinct from siblings like trmnl_update_playlist_item and trmnl_delete_playlist_item, though it does not explicitly route the agent away from them.
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 only guidance is 'Run only within the user-authorized scope,' which is an authorization constraint rather than a when-to-use rule. It does not explain when to choose this over trmnl_update_playlist_item, trmnl_reorder_device_playlist, or trmnl_bulk_update_device_playlist.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.