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

Annotations already declare destructiveHint=true, idempotentHint=false and openWorldHint=true, so the bar is lower. The description does add genuine behavioral context beyond them — the engine scores bids, picks a winner, and may perform an on-chain escrow verification — but it omits what happens to losing bids, whether closure is reversible, and what a failed on-chain check does.

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?

A single sentence that front-loads the action and then explains the mechanism and the optional branch. Nothing is wasted or repeated from the schema.

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, non-idempotent mutation with no output schema and a nested `escrow` object, the description leaves important gaps: no return value indications, no failure modes, and no statement of irreversibility. The core mechanics are covered, but an agent would still be guessing at the lifecycle consequences.

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 only 33%, but the one documented parameter (signature) is well described in the schema itself, and the description gives real meaning to the otherwise opaque `escrow` object by explaining it is an optional escrow authorization verified on-chain. need_id gets no explanation beyond the obvious. The description partially compensates for the coverage gap 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 ('Close a Match for a Need') and then describes the mechanism: running the match engine over bids and selecting a winner. That is enough to separate it from siblings like get_match (read) and submit_bid (write a bid). It stops short of contrasting itself with confirm_delivery, which is the nearest lifecycle neighbor.

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?

There is no explicit when-to-use guidance: nothing says the Need must be open, that bids must exist, who is authorized to close, or how this differs from the sibling confirm_delivery step. The phrase 'runs the match engine over its bids' only weakly implies the precondition that bids exist.

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