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

Beyond annotations, the description discloses that this is a hosted unsigned-transaction builder, signals that keypair bytes are never received, and explains exactly when transactionBase64 is returned (safeToApprove=true, approvalBlocked=false). This contextualizes the readOnlyHint=false annotation without contradicting it.

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 first paragraph is dense and front-loaded with the core purpose and return-condition. The second paragraph is structured SAP execution guidance with valuable routing and signing information, though it repeats boilerplate already present in the schema description.

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?

Given the rich schema and output schema, the description supplies the missing execution context: preflight checks, return-value gating, paid routing, and local-finalization boundary. No critical decision or call step needed to use the tool correctly is left unxplained.

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?

Input schema covers 100% of parameters with descriptions, so the baseline applies. The tool description adds global context (commodities pool, USDC collateral) but does not add parameter-specific detail beyond what the schema already provides.

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: 'Build an unsigned transaction to open a long position on a synthetic commodity (XAU, XAG, WTI) on Adrena.' It also specifies the commodities pool and USDC collateral, making the tool's scope clear and distinguishable from generic open/close position siblings.

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?

It explicitly states preconditions ('only after policy, balance, oracle-readiness, and simulation checks pass') and negative conditions ('if blocked diagnostics are returned, do not show approval or call finalize'). It also gives routing guidance: call sap_estimate_tool_cost first, use sap_payments_call_paid_tool when the runtime cannot handle x402, and finalize locally when signing is required.

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