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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering the safety profile. The description adds a small useful nuance by stating the data source is the 'catalog,' implying curated/pre-made content rather than arbitrary user data. This adds modest context but does not go further into behaviors like ordering or limits, which is acceptable for a 0-parameter list tool.

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?

A single five-word sentence with zero filler. The verb is front-loaded and every word ('List', 'Last Frame catalog', 'worlds/maps') carries meaning. No redundancy with the schema or annotations.

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 0-parameter read-only tool with an output schema, the description is mostly sufficient: safety is covered by annotations, return values are covered by the output schema, and the purpose is stated. The clear gap is the lack of differentiation from list_last_frame_games, which is a plausible source of agent confusion given the otherwise minimal context.

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 is an empty object with zero parameters, so there is no parameter documentation burden. Per the rubric, 0 parameters earns a baseline of 4; the description has nothing to compensate for since there is nothing to document.

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 ('List') and a recognizable resource ('Last Frame catalog worlds/maps'), so an agent can tell what the tool returns. However, it does not explicitly differentiate itself from the closely-related sibling list_last_frame_games, leaving the distinction to name inference.

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?

There is no guidance on when to use this tool versus alternatives like list_last_frame_games, list_library, or list_public_products. With 70+ siblings and several other list_* tools, the description gives the agent no explicit selection criteria or exclusions.

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