sign_transaction

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively communicates key behavioral traits: that signing requires a wallet's private key, that it returns different formats for different chains (hex for EVM, base64 for Solana), and that it does NOT broadcast transactions. However, it doesn't mention error conditions, rate limits, or authentication requirements.

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 perfectly concise with three sentences that each serve a distinct purpose: stating the core function, specifying return formats for different chains, and providing critical usage guidance. There is zero wasted language or redundancy.

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 complex transaction signing tool with 10 parameters and no output schema, the description provides good context about what the tool does and when to use it. However, it doesn't explain what happens with the signed transaction output or provide examples of typical next steps after signing, which would be helpful given the absence of an output schema.

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 10 parameters thoroughly. The description adds minimal parameter-specific information beyond what's in the schema, mainly clarifying the different return formats for EVM vs Solana. This meets the baseline expectation when schema coverage is complete.

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 specific action ('sign a transaction with a wallet's private key'), identifies the resource (transaction), and distinguishes from sibling tools by explicitly contrasting with 'send_transaction' for sign+broadcast. It provides clear differentiation from related operations.

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 provides explicit guidance on when to use this tool ('sign a transaction') versus when to use an alternative ('use send_transaction for sign + broadcast'). It clearly defines the tool's scope as signing-only and directs users to the appropriate alternative for broadcasting.

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