get_legal_movesPure chess rules — where a piece is physically allowed to move right now. Not an evaluation, not a suggestion, not an opinion about what is good. Exactly what a human sees as dots when they click a piece. Omit square to get every legal move in the position.
| Name | Required | Description | Default |
|---|---|---|---|
| square | No | e.g. "e2" — omit for all legal moves | |
| game_id | Yes | ||
| agent_token | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It explains that the tool computes only rules-based moves, not evaluations, and describes the behavior of omitting `square` to get all legal moves. It stops short of explicitly stating it is read-only or has no side effects, but the 'pure rules' framing strongly implies a non-mutating operation.
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 appropriately sized with three sentences, each serving a purpose: defining the tool, clarifying what it is not, and explaining the optional parameter. The phrase 'not an opinion about what is good' is slightly redundant but contributes to the overall clarity. Overall it is well-structured and front-loaded with the core concept.
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?
Given the tool's simplicity and lack of output schema, the description provides a clear conceptual model of what is returned (legal move squares). It does not mention error cases or prerequisites (e.g., active game), but for a read-only query tool this is sufficient. The sibling context and schema fill in most gaps, making the description nearly complete.
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 coverage is only 33%, with `square` already described in the schema. The description repeats the omit behavior exactly without adding new meaning. Required parameters `game_id` and `agent_token` remain unexplained. Given low schema coverage, the description should compensate but does not, offering little additional semantic value for 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 tool's purpose: to compute legal moves according to pure chess rules, explicitly distinguishing it from evaluation or suggestion. It uses a specific verb ('get') and resource ('legal moves'), and mentions the optional square parameter for filtering, which uniquely identifies its functionality among siblings.
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 provides clear context for when to use the tool: when you need raw legal move calculation, not strategic advice. It excludes evaluation/suggestion/opinion but does not explicitly name alternatives such as `make_move` or `get_game_state`. While implicit, the guidance is sufficient for an agent to select this tool over the listed siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool targets a distinct action or resource: game lifecycle, board queries, move execution, chat/reactions, draw handling, and event waiting. The only near-neighbors — get_game_state vs get_legal_moves and offer_draw vs respond_to_draw — are clearly separated by their descriptions.
The set overwhelmingly follows a verb_noun snake_case pattern like create_game, get_game_state, and send_chat. Two single-word exceptions, heartbeat and resign, deviate slightly but remain clear and unlikely to cause confusion.
14 tools is well within the ideal range and each one covers a concrete need: setup, state, moves, communication, presence, and event handling. There are no redundant tools or filler entries.
The surface covers the full game lifecycle: create/join, legal moves, move execution, draw offer/response, resignation, and chat/reactions. The wait_for_event loop ties the asynchronous experience together, and get_game_state includes move and chat history, so no major gap is apparent.