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

Annotations already mark the tool readOnly, idempotent, and non-destructive. The description adds meaningful behavioral details beyond that: fromAmount must be a string and numbers are rejected; without wallet addresses only a price-only quote is returned; including both addresses returns an unsignedTransaction; hosted builders never receive keypair bytes and value-moving results must be finalized locally. No contradiction with the annotations.

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 tool-specific first paragraph is tight and front-loaded with the core purpose and critical constraints. The second paragraph repeats SAP MCP execution guidance that is also present in the input schema description, introducing some redundancy, but the overall structure remains readable and not excessively long.

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?

With an output schema present and annotations covering safety and idempotency, the description fills the remaining operational gaps: canonical-mint resolution, base-unit string requirements, address-dependent transaction output, and the paid-builder payment/signing boundaries. Nothing critical is missing for an agent to invoke the tool 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?

The input schema already describes all five parameters with 100% coverage, including the string/base-units format and the address-dependent unsignedTransaction behavior. The description mostly recapitulates this, adding only narrative emphasis (e.g., 'numbers are rejected'), so it adds marginal meaning beyond the schema. Baseline 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 and resource: 'Get Sunrise swap quotes between two canonical mints.' It also clarifies that fromToken/toToken are mint addresses and fromAmount is a string in base units, which precisely scopes the operation. It differentiates itself from swap-execution siblings by noting it returns a quote or unsignedTransaction, not an executed trade.

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 gives explicit preconditions: resolve symbols first with sap_sunrise_resolve_token, and include fromAddress+toAddress to receive a signable transaction. It also frames the tool as a read/discovery workflow and provides paid-builder routing guidance (estimate first, call sap_estimate_tool_cost, use sap_payments_call_paid_tool when needed). It doesn't explicitly contrast with alternative quote tools such as jupiter_getQuote, so it stays just short of a 5.

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