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

The description goes well beyond the annotations by warning that this involves 'Real funds,' requiring explicit user confirmation, and explaining that place_order refuses execution unless a matching preview ran within 10 minutes. It also discloses the prerequisite that Agent Trading must be enabled, adding context not present in the schema or annotations. No contradiction with readOnlyHint=false or destructiveHint=true.

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 three sentences with no filler. The first sentence states the purpose, the second front-loads the critical safety workflow (preview before order, confirmation, refusal rule), and the third states the prerequisite. Every sentence earns its place and the structure is easy to scan.

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 high-stakes, destructive order placement tool with nine parameters and no output schema, the description covers the essential context: when to use it, the mandatory preview flow, user confirmation, the 10-minute expiry, and required settings. It also names the sibling preview_order to route the agent correctly. No critical gap is apparent.

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 already documents all nine parameters thoroughly. The description does not add parameter-level meaning, but the mention of 'with the same arguments' ties the parameters to the preview step, offering a small degree of additional context. This meets the baseline for a fully self-documenting schema.

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 opens with a specific verb and resource: 'open a perp position or place an order on Hyperliquid via MCPify.' It clearly distinguishes this tool from siblings like cancel_order, close_position, and preview_order by defining the exact user intent that triggers it.

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 explicitly states when to use the tool — when the user asks to open a perp position or place an order — and provides an explicit alternative: 'ALWAYS call preview_order with the same arguments first.' It also gives a hard precondition (matching preview within 10 minutes) and a configuration requirement (Agent Trading enabled), leaving no ambiguity about sequencing.

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