hl_cancel_order

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

No annotations are provided, so the description carries the full behavioral burden. It adds the useful constraint that the target must be a resting (open) order, but says nothing about required permissions, irreversibility, what happens to partially filled orders, or what the call returns on success/failure.

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 with the action front-loaded and zero filler; the descriptive clause about oid source earns its place by resolving the required input.

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 simple two-parameter cancel tool with fully documented schema and no output schema, the description supplies what an agent needs to call it: the action, its single-order scope, and the source of the oid. Only the mutation's side effects and failure behavior are left unaddressed.

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 both parameters are already documented in the schema, and the annotation-free description adds only the provenance of oid (openOrders) on top of that. Baseline 3 is appropriate when the schema does the heavy lifting.

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 (cancel) and resource (one resting order), plus scopes it to a single order rather than a bulk operation, which cleanly separates it from hl_place_order. The reference to the oid's origin further pins down exactly what entity it operates on.

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 tells the agent where the required oid comes from (hl_account with kind=openOrders), which is real usage guidance for invoking it correctly. It stops short of naming when not to use it or any alternative route, so it is clear context rather than full when/when-not guidance.

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