token4u_chat

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

With no annotations, the description carries the burden of behavioral disclosure. It reveals that each call is paid per-model via an EIP-3009 authorization from the local wallet, and that a wallet must exist. This is critical operational context. It doesn't mention return format or errors, but the payment trait is well covered.

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?

Three sentences, each earning its place: purpose and payment mechanism, per-model pricing, and prerequisite. No fluff 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?

Given no output schema or annotations, the description covers the key aspects: what the tool does, how payment works, and what is required before calling. It doesn't explicitly state the response format, but 'chat' implies a model reply. Overall sufficient for a paid chat 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 schema already provides descriptions for model, max_tokens, and temperature (75% coverage). The description adds an example model name and clarifies per-model pricing, but does not add significant meaning for the messages parameter or further parameter syntax. Baseline 3 is appropriate.

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 uses a specific verb ('Chat'), specifies the resource ('AI models via token4u'), and adds the payment mechanism (x402 micropayments). This clearly differentiates it from sibling tools like token4u_wallet (wallet management) and token4u_consumption (usage tracking).

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 a clear prerequisite: run token4u_wallet action=create first. It implies this tool is for chat actions requiring payment, but does not explicitly mention when to prefer this over token4u_consumption. Still, the wallet requirement is practical guidance.

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