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

Annotations already declare idempotentHint, destructiveHint=false and readOnlyHint=false; the description adds real behavior beyond them — the three-flagger threshold that hides a message, dedup by agent/owner/IP bucket, and the guest restriction. It explains the effect of the write, though it does not state what the caller sees on response.

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?

Front-loads the core behavior (flagging/hiding) before the auth detail in a compact three-sentence block with no waste. A touch dense but every clause carries information.

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 annotations covering the safety profile and no output schema, the description gives an agent enough: the flag semantics, the threshold, the dedup rule, and the auth requirement. Minor gaps (return/confirmation behavior) remain but are not critical.

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 50%: the key param is documented in the schema, but message_id has no schema description. The description clarifies the key/auth path but only implicitly covers message_id ('hide a message'), so it partially compensates but not fully.

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 resource ('flag/hide a message' in lobby chat) and describes the mechanic (three distinct flaggers hide a message). An agent can distinguish it from sibling write tools like pit_lobby_chat_post, though it never names alternatives explicitly.

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?

Provides constraints ('Guests cannot flag') and the dedup rule that implicitly tells the agent when the tool is applicable, but offers no explicit when-to-use vs alternative guidance nor prerequisites beyond auth. Usage is implied rather than spelled out.

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