Check Saved Albums

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

Annotations already declare this as read-only, idempotent, and open-world. The description adds valuable behavior beyond that: the per-request album cap (20, contrasted with Spotify's 50 for tracks) and the response behavior that maps each album ID to true if saved. This is useful context without contradicting the 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?

The description is compact and well-organized: purpose first, then the batch limitation, then Args and Returns. Every sentence earns its place and there is no redundant or promotional language.

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 simple one-parameter, read-only tool with an output schema and supportive annotations, the description covers the key facts an agent needs: what the tool does, accepted argument format, the request cap, and the shape of the result. Minor omissions like explicit behavior for false membership or invalid IDs are acceptable given the output schema exists.

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 input schema only declares an array of strings with no per-parameter documentation, so the description carries the burden. It compensates well by specifying that album_ids accepts 'Album IDs or URIs' and that the maximum is 20 items. It could be even stronger with an example or explicit note about mixing IDs and URIs, but it is sufficiently informative.

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 opens with a specific action and resource: 'Check which albums are already saved to the library.' This clearly identifies the tool as a membership-checking operation for albums, which is enough to distinguish it from nearby siblings like check_saved_tracks or get_saved_tracks, though it does not explicitly name 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 description provides a practical constraint ('One request for up to 20 albums') but does not explain when an agent should choose this tool over alternatives such as check_saved_tracks or save_tracks. There is no explicit when-to-use or when-not-to-use guidance, only an implied use case from the first sentence.

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