add_to_playlist

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

With no annotations, the description carries full burden. It transparently discloses batching (100 tracks per request), error handling (ValueError for empty track_uris, SpotifyException propagation), and return format. However, it omits permission requirements (e.g., playlist ownership/collaboration) which are relevant for a mutation tool.

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 well-structured with clear sections for Parameters, Returns, and Raises. No fluff, every section adds necessary info, and it is appropriately concise for the tool's complexity.

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 covers purpose, parameters, returns, and exceptions, making it fairly complete for a simple tool. However, it lacks context about prerequisites like playlist access/ownership, and does not clarify overlap with search_and_add, leaving minor 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?

The description provides detailed parameter documentation beyond the input schema, including accepted formats ('Spotify playlist ID or full URI', 'track URIs or bare track IDs'). Since schema description coverage is 0%, this fully compensates and enhances meaning.

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 clearly states 'Add one or more tracks to an existing Spotify playlist', using a specific verb and resource. This distinguishes it from siblings like add_to_queue (adds to queue) and create_playlist (creates new playlist).

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 adding tracks to playlists but does not explicitly specify when to use it over alternatives like add_to_queue or search_and_add. No exclusion or alternative guidance is provided, making usage context clear only by implication.

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