list_games

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the agent knows this is a safe, self-contained read. The description adds that the response enumerates move formats and per-game algorithms, which is genuine context about what the listing contains. It stops there, offering no pagination, ordering, or filtering context, so a 3 is appropriate with annotations carrying the safety profile.

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 clause-rich sentence with no filler, and the core purpose ('List the games') is front-loaded before the details of what the listing returns. Every element 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?

With an output schema present, the description need not spell out return values, and with zero parameters there is no input surface to document. The description covers purpose and payload adequately; the only missing piece is routing guidance between siblings, which is minor for a discovery tool.

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 tool takes no parameters, so there is nothing for the description to disambiguate and no schema-coverage gap to compensate for. Baseline 4 applies for a zero-parameter tool.

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 pairs a specific verb ('List') with a specific resource ('the games you can play') and further states the payload: move format and available algorithms. This clearly separates it from action-oriented siblings like play_move or new_game. It stops short of explicitly naming which sibling to use instead, so it is not a 5.

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 statement of when to call this versus alternatives such as get_rules or new_game, and no prerequisites or exclusions are given. The discovery role (call before starting a game) is only inferable from the word 'List'. This matches the mid-tier calibration where absent when-to-use guidance scores 2.

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