List playlists

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

The description adds value beyond the readOnlyHint annotation by explaining that playlists are private per user (no cross-user access) and can contain different item types. It also clarifies the scope change with library_id. This is sufficient for a read-only listing operation.

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 only three sentences, each earning its place: first sentence defines scope, second handles the parameter behavior, third clarifies the distinction between playlists and collections. No wasted words.

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 the low complexity (2 optional params, no output schema, read-only), the description covers the essential semantics: ownership, item types, parameter behavior. It could mention ordering or pagination if applicable, but the tool likely returns all playlists, so the description is complete enough.

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 coverage is 100% and the description already provides the key behavioral context for library_id (empty vs set). For detail, the schema's enumerated values and descriptions are clear; the description doesn't need to repeat them. Thus the description adds useful conceptual context without redundancy.

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 the tool lists playlists for the API key's user, distinguishing between playlists (private, can hold books or podcast episodes) and collections (shared, books only). It also mentions the optional library_id parameter's effect, making the purpose specific and unambiguous.

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 explains when to use it (listing playlists) and the effect of including library_id versus omitting it. However, it does not explicitly state when not to use this tool or mention alternatives like list_collections for shared items, which would be helpful given the sibling tools.

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