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

Annotations disclose the safety profile (not read-only, not destructive, idempotent, open world), so the bar is lower. The description still adds value beyond them: it states that positions and their stops persist at the broker, and that the call is refused mid-flight — both behavioral facts absent from the 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?

Three tight sentences with zero filler: scope and side-effect first, the failure condition second, a call example third. Nothing is redundant and the critical constraint is front-loaded.

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?

Covers the two things an agent most needs for this mutation: what persists (positions/stops) and the blocking condition (in-flight order). An output schema exists so return values needn't be described, and annotations carry the idempotency/destructiveness profile. Minor gap: no mention of whether the account can be brought back online or what states are invalid.

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 single UUID parameter is fully documented in the schema, including the important "not the MT5 login number" disambiguation. The description only repeats the parameter inside a JSON example, adding no syntax or meaning beyond the schema, so the baseline 3 applies.

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 ("Stops an account's terminal") and immediately clarifies scope by noting open positions and stops stay at the broker, which distinguishes it from closure tools like close_position. It does not explicitly name the sibling it inverts (bring_accounts_online), so it stops short of full sibling differentiation.

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?

"Refused while an order is in flight" is an explicit precondition that tells the agent when the call will fail, which is genuine when-not guidance. It does not name an alternative tool or describe when this should be preferred over simply leaving the account online.

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