add_favorite_album

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

No annotations are provided, so the description carries the full burden. It discloses the auth requirement, the duplicate-favorite behavior (returns error and does not change state), and the meaning of the returned message field. This goes well beyond a minimal mutation description.

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 a short action statement followed by compact Parameters and Returns sections. Every sentence adds meaningful information, and the key duplicate behavior is noted early.

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 one-parameter favorite-add tool, the description covers the auth prerequisite, side effects, parameter normalization, and the full return contract. There are no critical operational gaps given the tool's simplicity.

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 gives album_id as a string, so the description adds essential semantics: it accepts an album ID, a JM prefix, or an album link, and normalizes to a pure numeric string. This is exactly the enrichment an agent needs to invoke the tool correctly.

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 uses a specific verb and resource: add an album to the current logged-in account's favorites. It clearly differentiates from sibling tools like delete_favorite_album and browse_favorite_albums.

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 states a clear prerequisite: a valid login session or Cookie is required. It does not explicitly name alternatives or say when not to use the tool, but the action is unambiguous and the sibling names make the distinction evident.

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