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

Adds substantial detail beyond the annotations: login requirement, irreversibility ("发出去收不回"), the 10/rolling-24h rate limit shared with update_broker_match, and that an already-introduced match returns the original conversation without consuming quota. This directly corroborates destructiveHint=true and idempotentHint=true with the specific consequences rather than restating them.

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 ⚠ irreversibility warning is front-loaded and the highest-value information leads. It is dense with semicolon-joined clauses, but nearly every clause carries operational information; it is crowded rather than padded.

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 destructive, open-world mutation tool with no output schema, the description covers prerequisites (login), safety (irreversibility, confirmation step), limits (quota), edge cases (already introduced), and the alternative for off-platform parties. Nothing essential to invoking it correctly is missing.

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 baseline is 3, but the description goes further: it warns that message must be self-finalized and that omitting it sends a default matchmaking reason or fallback text, and reiterates that the message is read aloud for confirmation. That adds real behavioral meaning about the optional parameter.

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 concrete verb and resource: creates a 3-person group A × B and sends the first message under the user's own name. It explicitly differentiates from related siblings (create_broker_match upstream, send_message downstream, get_broker_intro_scripts for the off-platform case).

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?

Gives explicit when conditions: only when both parties are on-platform, otherwise use get_broker_intro_scripts. It also prescribes the exact workflow (create_broker_match → get_broker_intro_scripts → confirm → this tool → send_message) and that execution is one at a time, not batched.

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