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

Annotations already declare destructiveHint=true, readOnlyHint=false, idempotentHint=false and openWorldHint=true, so the safety profile is covered. The description adds real value beyond that by explaining the consequence (the order cannot be authorized or auto-executed) and the state constraint (pending only), which also implicitly explains the non-idempotent behavior.

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?

Two tight sentences with zero filler. The core action is front-loaded, with the consequence following and the state restriction last as a natural qualifier.

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 mutation tool with full annotation coverage, the description supplies the action, the effect on downstream authorization/auto-execution, and the state precondition. No output schema exists, so return behavior is unspecified, which is a minor gap for a destructive operation.

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 description coverage is 100% and the single 'id' parameter is documented there as the suggested order ID from get_suggested_orders. The description adds no format, sourcing, or semantic detail beyond the schema, so the baseline of 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?

The description names a specific verb ('Withdraw') and resource ('PENDING order to authorize (suggested order)') and clarifies what the operation prevents ('no longer be authorized or auto-executed'). The term 'suggested order' implicitly distinguishes it from the sibling cancel_broker_order and cancel_conditional_order, though no sibling is named 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?

'Only pending orders can be cancelled' gives a meaningful precondition for successful use. However, it offers no routing guidance — an agent is not told when to prefer this over the sibling cancel tools or what to do for non-pending orders, leaving usage partially implied.

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