get_now_playingReturns the song currently on air: title, artist, album, artwork URL, start time, and stream URL.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
| art | Yes | ||
| album | Yes | ||
| title | Yes | ||
| artist | Yes | ||
| elapsed_s | Yes | ||
| duration_s | Yes | ||
| started_at | Yes | ||
| stream_url | Yes |
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -nullNew value: +{
+ "$schema": "http://json-schema.org/draft-07/schema#",
+ "additionalProperties": false,
+ "properties": {
+ "album": {
+ "type": [
+ "string",
+ "null"
+ ]
+ },
+ "art": {
+ "anyOf": [
+ {
+ "format": "uri",
+ "type": "string"
+ },
+ {
+ "type": "null"
+ }
+ ]
+ },
+ "artist": {
+ "type": [
+ "string",
+ "null"
+ ]
+ },
+ "duration_s": {
+ "type": [
+ "number",
+ "null"
+ ]
+ },
+ "elapsed_s": {
+ "type": [
+ "number",
+ "null"
+ ]
+ },
+ "started_at": {
+ "type": [
+ "string",
+ "null"
+ ]
+ },
+ "stream_url": {
+ "anyOf": [
+ {
+ "format": "uri",
+ "type": "string"
+ },
+ {
+ "type": "null"
+ }
+ ]
+ },
+ "title": {
+ "type": [
+ "string",
+ "null"
+ ]
+ }
+ },
+ "required": [
+ "title",
+ "artist",
+ "album",
+ "art",
+ "started_at",
+ "elapsed_s",
+ "duration_s",
+ "stream_url"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, openWorldHint, idempotentHint, destructiveHint. Description adds specific return fields (title, artist, etc.), providing additional behavioral context beyond annotations.
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?
Single, clear sentence front-loaded with purpose. 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?
Given zero parameters, strong annotations, and an output schema, the description fully captures what the tool does and returns. No 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?
No parameters; baseline 4 is appropriate. Description adds nothing about parameters because none exist.
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?
Description uses specific verb 'returns' and identifies resource 'song currently on air', listing all relevant fields. Clearly distinguishes from siblings like 'get_rewind' or 'search_song_history'.
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 explicit when-to-use or when-not-to-use guidance. Usage is implied by context of 'now playing', but no alternatives or exclusions mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.