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

With no annotations, the description carries the full burden and does well: it discloses the five-minute EIP-191 message, the Base USDC approve-zero/transfer-zero alternative, and that 402Mob never receives a private key. It still omits permissions, error behavior, and rate limits, but adds substantial behavioral context.

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 front-loaded and efficient: four sentences cover the action, return value, next steps, alternative path, and security note without filler.

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 no-annotation tool with no output schema, it explains the returned message and API key handling well. The main gap is the unexplained name parameter and some operational details, but the enrollment flow is otherwise clear.

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 explain the two parameters. It refers to signing with the 'merchant wallet', which loosely maps to wallet, but it never explains the name parameter or its constraints, leaving half the parameters undocumented.

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: 'Begin headless merchant enrollment.' It also names the downstream completion tools, making it easy to distinguish this challenge-creation step from the complete_* siblings.

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 explicitly gives two valid paths: sign the exact message and call complete_merchant_enrollment_signature, or use the wallet action and call complete_merchant_enrollment_transaction. That is clear when-to-use guidance with named alternatives.

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