build_transaction

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

With no annotations provided, the description carries the full burden. It discloses key behaviors: the tool builds an unsigned transaction with gas estimates, handles native and ERC-20 tokens, and has a cost ('Price: $0.15'). However, it lacks details on permissions, rate limits, error conditions, or what 'ready for signing' entails (e.g., format). It doesn't contradict annotations, but gaps remain for a mutation tool.

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 well-structured and front-loaded with the core purpose. The Args/Returns sections efficiently document parameters and output. The 'Price' line adds necessary context. It's slightly verbose but each sentence earns its place, with no redundant information.

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 complexity (transaction building with 5 params), no annotations, but an output schema exists (implied by 'Returns'), the description is reasonably complete. It covers purpose, parameters, output, and cost. However, for a mutation tool, it could better explain behavioral aspects like side effects or error handling to fully compensate for missing annotations.

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 0%, so the description must compensate. It adds meaningful semantics for all 5 parameters: explaining 'from_address' as sender, 'to_address' as recipient, 'value' in token units/wei, 'chain' as blockchain network, and 'token_address' as optional for ERC-20 vs. native. This clarifies beyond schema titles, though it could specify formats (e.g., hex for addresses).

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: 'Build a transaction object ready for signing.' It specifies the action (build), resource (transaction object), and outcome (ready for signing). However, it doesn't explicitly differentiate from sibling tools like 'bridge_tokens' or 'manage_approvals', which might also involve transaction building in different contexts.

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 no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing wallet access), exclusions, or comparisons to siblings like 'bridge_tokens' for cross-chain transfers or 'manage_approvals' for token approvals. Usage is implied but not explicitly stated.

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