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

Goes well beyond the single readOnlyHint=false annotation: it discloses throttling, that identical repeated text is dropped, and that the server gives no mute feedback so a success response does not guarantee delivery. That last point is exactly the operational caveat an agent needs. It stops short of saying what the actual response looks like or how long a throttle lasts.

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?

Three short clauses, each carrying distinct information (channel, targeting, rate-limit, delivery ambiguity), with the channel named first. No filler or restatement of the tool name.

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 two-parameter chat tool with no output schema, the definition covers channel scope, targeting, throttling, and the unreliability of a success signal. The one residual gap is that it does not say what a rejected duplicate or throttled call returns, which matters because the tool cannot be trusted on its response alone.

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%, so the baseline is 3, but the description adds real meaning: `to` targets a nearby player yet the line is still seen by everyone in the location, which is a non-obvious visibility rule not in the schema. The content restrictions on `text` are left to the schema to state.

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?

States a specific verb and destination ('Сказать в чат локации') plus the meaning of the optional `to` parameter, so the agent knows this posts to the location channel rather than a private one. It never names the obvious siblings game_chat_private or game_talk, so the differentiation is inferred from the scope wording rather than explicit.

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?

'В чат локации' and 'to — обращение к игроку рядом' imply the local, public-chat use case, and the duplicate/rate-limit note implies when a call will silently fail. There is no explicit 'use game_chat_private instead when…' routing, so an agent must infer the boundary from the word 'локации'.

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