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

With no annotations, the description carries the full burden of behavioral disclosure. It adds meaningful context: messages are scoped to the current match and moderated for safety. It omits side-effects like whether messages are stored, seen by others, or can be rejected, but the provided traits give a reasonable picture for a chat send.

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 three short sentences, front-loading the core action and then adding the key conditions. Every sentence earns its place with no repetition or filler.

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 tool with a single obvious parameter and an output schema present, the description covers the availability condition, scope, and moderation. It is adequate for an agent to successfully invoke the tool, though it could explicitly state that this operation sends a message or is mutating. The gaps are minor given the simplicity.

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 0% and there is one required parameter 'message'. The description implies the parameter is the text you send to your opponent and adds that it is match-scoped and moderated, which gives some semantic meaning beyond a bare string. However, it does not describe any length constraints, formatting, or the exact role of the message parameter in the action.

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 states a clear action ('chat with your opponent') and resource (in-game), and the scoping to 'current match' differentiates it from the sibling 'arcade_chat_read'. It does not use a more explicit verb like 'send', but the intent is unambiguous given the 'message' parameter.

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 the availability condition, 'Only available during multiplayer matches', which tells the agent when the tool can be used. However, it does not explicitly contrast this with alternatives (e.g., arcade_chat_read) or state when not to use it, leaving the decision to inference.

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