build_token_transfer

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

With no annotations, the description carries full burden. It discloses that the output is unsigned calldata (so no signing) and that amount is parsed against token decimals with refusal of over-precise amounts. This is valuable behavioral info, though return format (hex string) is not mentioned.

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?

Two sentences with no fluff. First sentence front-loads the core purpose, second adds important behavioral detail. Every word earns its place.

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 no output schema, the description is missing the return format (e.g., hex-encoded calldata string). It also does not address error cases (e.g., invalid token, insufficient balance). For a calldata builder, this is a minor but notable gap.

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 coverage is 0%, so description must compensate. It mentions 'token', 'to', 'amount' implicitly and adds decimal handling for amount. However, it does not explain that 'to' is recipient address, 'amount' is decimal string, or format expectations. Partial compensation.

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 verb 'Build', the resource 'UNSIGNED calldata for an ERC-20 transfer', and includes critical qualifiers like 'real decimals' and 'over-precise amounts refused'. This distinguishes it from siblings like build_transaction (native ETH) or build_token_approve.

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?

While the description implies it is for ERC-20 transfers only, it does not explicitly state when to use this tool versus alternatives (e.g., build_transaction for ETH, build_token_approve for approvals). No when-not-to-use or context provided.

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