Chat completions with x402 payment

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

Annotations are all false and carry no safety signals, so the description does the heavy lifting. It clearly discloses the required payment flow (x402, first call returns 402, retry with _meta['x402/payment']), non-streaming responses, and max_tokens clamp/default behavior.

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 information-dense but each sentence earns its place. Payment requirement and routing rules are front-loaded before the 'Use this tool…' usage note. No filler or repetition.

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 paid mutation-style tool with no safety annotations, the description covers all prerequisites, parameter selection, defaults, and which sibling to use instead. Combined with an output schema existing, nothing an agent needs to call it correctly is missing.

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?

Even though schema coverage is 100%, the description adds meaningful semantics: explains auto/eco/premium routing, mutual exclusivity with model, model wins if both, and max_tokens default/clamp. This goes beyond the schema's basic type/enum definitions.

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?

Opens with a specific verb and resource: 'Send a chat completion request to any supported model.' It also frames it as the text-generation tool, opposite to the free inspection tool list_models, so the agent can immediately distinguish it from its 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?

Explicitly says to use this for text generation and to use free list_models first to inspect models and prices. It also explains the mode-vs-model selection, which is essential for correct invocation.

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