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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the description's 'Read-only' is redundant. However, it adds valuable context that annotations do not cover: 'no signing needed' and 'free', which are operational constraints an agent must know. This extra information justifies a score above the baseline.

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?

The description is a single sentence of 20 words that front-loads the core action and scope. Every element (read, all open perpetual positions, wallet, GMX v2, Arbitrum) is necessary; there is no filler or redundancy.

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 read-only tool with one parameter, 100% schema coverage, and a provided output schema, the description is complete. It specifies the network and protocol, which are critical for correct invocation, and the annotations cover safety and idempotency. No missing information would prevent an agent from calling it correctly.

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%, so the schema fully documents the 'wallet' parameter as a '0x… Arbitrum wallet address to check'. The description merely repeats 'wallet' without adding syntax, format, or behavior details beyond the schema. Since the schema does the heavy lifting, a baseline of 3 is appropriate.

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 states a specific verb ('read'), a precise resource ('all open perpetual positions'), and scopes it to 'a wallet on GMX v2 (Arbitrum)'. This clearly differentiates from sibling tools like gmx_get_orders or gmx_get_prices, which handle different aspects of the protocol.

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 provides clear context by specifying that this tool reads perpetual positions, which implies its appropriate use case. However, it does not explicitly compare to alternatives (e.g., 'use gmx_get_orders for orders') or state when not to use it, leaving some inference to the agent.

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