Add or remove a game from lists

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

Annotations already indicate a non-read-only, idempotent, non-destructive write operation. The description adds meaningful context by revealing the 'one call' combined add/remove capability and the dependency on get_lists for IDs. It does not contradict annotations and provides useful behavioral details beyond structured metadata.

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 two short sentences with no filler. The first sentence front-loads the core functionality (add/remove in one call), and the second provides a crucial dependency (get_lists). Every word earns its place.

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 moderate-complexity tool with 3 parameters and no output schema, the description covers the essential behavior, the source of list IDs, and the combined operation. Annotations and schema handle safety and types, so the description is sufficient, though it does not mention error handling or return values.

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?

With only 33% schema description coverage (only 'game' described), the description compensates by explaining that list IDs come from get_lists and that add/remove lists can be used together. While parameter names are self-explanatory, the description adds valuable guidance on sourcing IDs and combining operations, though it could be more explicit about semantics of the two list 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 the action: 'Add a game to lists and/or remove it from others in one call.' It specifies the resource (game lists) and the dual add/remove behavior, distinguishing it from sibling tools like create_list or delete_list by focusing on modifying membership in existing lists. The mention of get_lists as the ID source further clarifies its specific role.

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 a clear usage context: list IDs come from get_lists, so this tool should be used after fetching lists. It also signals that add and remove can be combined in a single call. However, it does not explicitly state when not to use it or name alternatives, so it falls just short of a 5.

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