order_preview

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

The description discloses all key behavioral traits: read-only, top-of-book FAK, no executor/order creation, no budget reservation, and fee estimation behavior. Since no annotations are provided, the description fully fulfills the transparency burden.

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 concise with four sentences, no redundant information, and front-loads the core purpose ('Read-only top-of-book FAK preview'). Every sentence contributes essential detail.

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 tool with 4 parameters, no schema descriptions, no annotations, and an output schema, the description covers the core semantics and behavior. It omits details about the output structure, but the presence of an output schema mitigates this need. A perfect score would require more explicit guidance on output fields.

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?

The description adds crucial meaning to the parameters by explaining how 'amount' and 'price_limit' differ based on the 'side' (BUY vs SELL). This is not available in the schema, which has 0% description coverage.

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 clearly states the tool is a 'read-only top-of-book FAK preview' and explicitly distinguishes it from order-execution tools by stating it never creates an executor, sends an order, or reserves budget. This provides a clear verb+resource definition and differentiates it from siblings like order–related tools.

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 indicates when to use the tool (to preview an order) and what it does not do (no order creation). However, it lacks explicit comparisons to sibling tools or conditions for not using it, which would raise the score to 5.

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