Apply a move to the game and return the new state. Pass the move object exactly as returned by play_get_moves (format varies by family: chess uses {from,to}, go uses {coord} or {action:"pass"}).
| Name | Required | Description | Default |
|---|---|---|---|
| move | Yes | Move object from play_get_moves (e.g. {from:"e2",to:"e4"} for chess, {coord:40} for go, {action:"pass"}) | |
| state | Yes | Game state object from play_create_game or a previous play_apply_move |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It discloses that the tool applies a move and returns a new state, and notes format variability. However, it doesn't mention whether the original state is mutated, error behavior for invalid moves, or any side effects, which are important for a mutation 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?
Two sentences, front-loaded with the core action and outcome, followed by concise format guidance. No filler or repetition of schema fields, making it very efficient.
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 simple 2-parameter tool, the description covers the core behavior, return value, and input sources, and gives examples for varying families. It lacks error-handling details but given no output schema, it adequately explains the new state. It is not comprehensive, but sufficient for the tool's complexity.
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 100%, with both parameters described in the schema including examples. The description adds the constraint 'exactly as returned by play_get_moves' for the move parameter, reinforcing the source, but doesn't significantly augment the schema's meaning for the state parameter. It meets the baseline for high schema coverage.
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 verb 'Apply' and the resource 'a move to the game', with a specific outcome 'return the new state'. It distinguishes itself from siblings like play_get_moves (which retrieves moves) by implying this tool executes a move. The mention of family-specific formats adds specificity.
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?
It provides clear usage context by instructing to pass the move object 'exactly as returned by play_get_moves', and implies the state comes from play_create_game or previous apply. However, it doesn't explicitly contrast with alternatives like play_make_moves or state when not to use it, so it doesn't fully cover exclusions.
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.
Most tools have clear prefixes (chess_, play_, hex_, oracle_, rpg_, ti4_) that separate concerns, but overlap exists between deprecated chess_* tools and the newer play_* equivalents, plus rpg_random_encounter and oracle_encounter both generate encounters. Descriptions help disambiguate, but the redundancy could mislead agents.
Many tools follow a domain_verb_noun pattern (hex_generate_map, play_get_moves, rpg_search_entities), but there are notable exceptions like dice_roll, game_deck_create, jam_status, and random_player_order that mix noun-first and verb-last conventions. The inconsistent ordering makes it harder to predict tool names.
81 tools is excessive even for a broad games toolkit; the deprecated chess_* tools alone add unnecessary bulk. While the scope is wide, the count exceeds practical limits and could be consolidated into fewer, more focused tools.
The toolkit covers a wide variety of game needs: dice, cards, hex maps, chess, RPGs, TI4, jam management, and galleries. Minor gaps like the score tracker lacking a retrieval method and the absence of some lifecycle operations keep it from being perfect, but core workflows are well covered.
