jellyfin_add_to_collection

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

With no annotations, the description carries full behavioral disclosure. It explains that duplicates are reported and skipped, and the confirm flag controls whether writes occur. This provides useful behavioral traits, though it could clarify error handling for unresolvable references.

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 three sentences with no wasted words. The first sentence delivers the core purpose, and subsequent sentences add behavioral details in a logical order.

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 tool has moderate complexity with three parameters and an output schema. The description explains key behavior (duplicate handling, confirm flag) but omits the movies parameter format and any prerequisites. While output schema exists, the lack of complete param documentation reduces completeness.

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 description coverage is 0%, so the description must compensate. It clarifies 'collection_ref' as name or ID and explains 'confirm' behavior, but does not define the format of items in the 'movies' array (e.g., title, ID). This leaves a significant gap for one of three parameters.

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 movies to an existing collection,' using a specific verb and resource. It distinguishes itself from sibling tools like jellyfin_create_collection and jellyfin_remove_from_collection by focusing on adding to an existing collection.

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 mentions 'Same resolution ergonomics as jellyfin_create_collection' but does not explicitly state when to use this tool versus alternatives. It lacks exclusions or prerequisites, leaving the agent to infer usage context from the purpose.

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