svm_sign

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

With no annotations, the description carries full burden and does so well: it states the tool is local, adds only the source-authority signature, leaves feePayer unsigned for the facilitator, returns base64, and includes a security warning about key exposure. No contradictions with annotations exist since none are provided.

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 dense but each sentence provides necessary information: what it does, how it works, return value, and security context. It is slightly long, but the content earns its place and it is front-loaded with the primary purpose.

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 signer with no output schema and no params, the description covers the workflow, the exact behavior (partial-sign), the return shape, and the security caveat. It lacks error-condition details, but those are not essential for a single-action tool.

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 is empty, so the description is the only source of parameter info. It adds the secret key format (base58) and the policy that it is passed as a parameter (never from env), which is valuable. However, the transaction input itself is only implied, not explicitly named as a parameter.

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's purpose: 'Partial-sign a Solana (SVM) x402 payment transaction locally'. It uses a specific verb (partial-sign) and resource (Solana SVM x402 transaction), and it distinguishes itself from sibling chain-specific sign tools by focusing on the SVM/x402 context.

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 says exactly when to use it: when you have a base64 UNSIGNED TransferChecked tx from the x402 buyer /authorize, and explains the single action flow. It does not explicitly call out alternatives (e.g., 'use evm_sign for EVM'), but the sibling naming and chain-specific focus imply them.

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