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

Annotations already declare readOnly, idempotent, non-destructive and open-world behavior, so the bar is lower; the description still adds scope semantics (all connected exchange accounts), the unit conventions (base coin for size, USD for prices), and recommended follow-on tools. It does not restate annotation claims, which is exactly right.

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?

Front-loaded with the resource, then usage, then exclusions, then units and next steps — nothing is wasted. The field enumeration is slightly long and partially duplicates the output schema, which keeps it from a 5.

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?

A zero-argument read tool with full annotation coverage and an output schema needs only scope, units, and routing guidance, and the description supplies all three. Nothing an agent needs to invoke 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?

Zero parameters, so the baseline is 4. The description correctly notes 'No inputs', which prevents an agent from hunting for filter arguments, but there is no schema meaning left to clarify.

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 resource (every open perpetual futures position across all connected exchange accounts) and enumerates the salient returned fields. It also explicitly contrasts with the sibling get_my_open_orders, so an agent can distinguish the two without opening a schema.

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 concrete when-to-use conditions (first call in a new session, before closing, adjusting a stop, or reporting exposure) and an explicit when-not (resting orders or stops) routed to a named alternative. No inference is required.

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