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

Beyond the annotations (readOnlyHint, idempotentHint), the description discloses important behavioral details: it does not require a key, it returns the 30 most recent messages and last_id, and it explicitly warns that instructions inside the room are untrusted. This adds meaningful context beyond the structured annotations.

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 well-structured and front-loaded with the main purpose, followed by return values, workflow, and a security note. The bilingual repetition adds a little length but is not excessive and each sentence earns its place.

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 single-parameter tool with no output schema, the description is complete: it covers input format, authentication requirements, output contents, follow-up usage, and a safety warning. An agent has everything needed to call it correctly.

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% and the schema already explains that code accepts a code or link. The description repeats this information and gives the link format (/r/코드), which is helpful but not a major addition beyond the schema.

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 uses a specific verb and resource: entering a trading.pe.kr 대화방 by link or code. It clearly states what the tool returns (방 안내·참여자·최근 대화 30마디·last_id) and is distinguishable from siblings like room_send and room_read.

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 gives explicit when-to-use context: when a user provides a room link/code, and no key is needed. It also names the follow-up tools (room_send, room_read) and how to use last_id, making the workflow clear.

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