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.

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

With no annotations, the description carries the full burden of behavioral disclosure. It states the API is public and requires no login, and it lists the exact return fields (model, token usage, credits, amount paid in USD, transaction hash, timestamp). It does not mention rate limits or error handling, but for a read-only query this is reasonably transparent.

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 two sentences, front-loaded with the purpose, and includes only essential details (public API, return fields). Every sentence earns its place without waste.

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?

The description covers purpose, public access, and return fields, which is important because no output schema exists. For a simple query tool with three parameters, it is fairly complete. It lacks details on pagination behavior or error conditions, but the schema covers page/page_size and default values, so the description meets the core needs.

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 description coverage is 100%, and the description does not add significant new parameter semantics beyond what the schema already provides. The description mentions 'given EVM wallet address' which aligns with the address parameter but adds no additional detail about page or page_size beyond the schema's defaults.

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 queries x402 consumption records for a given EVM wallet address, using the specific verb 'Query' and identifying the resource and scope. This distinguishes it from sibling tools like token4u_wallet and token4u_chat, which likely handle wallet and chat functions respectively.

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 clear context for usage: it is a public API requiring no login, intended for querying per-call consumption records for a wallet address. It does not explicitly mention alternatives or when not to use it, but the context is sufficient for basic selection.

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

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

With no annotations provided, the description carries the full burden and does so thoroughly. It discloses the wallet file location and permissions (~/.token4u-mcp/wallet.json, 0o600), that the private key never leaves the machine, how create loads or generates a keypair, and the underlying network (Base USDC). This far exceeds the minimum required.

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 main purpose, followed by a concise context paragraph and an action list. Every sentence contributes useful information without fluff, making it scannable and appropriately sized for the tool's complexity.

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 it has only one parameter, no annotations, and no output schema, the description is exceptionally complete. It explains the tool's purpose, all three actions with their effects, underlying network details, security properties, and prerequisite context (no token4u account needed), leaving no critical gaps for an agent to select and invoke it correctly.

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?

Although the schema covers the single parameter 'action' with an enum and description, the description adds substantial meaning by explaining what each enum value does: status shows address/newly-created flag, create generates/loads a keypair with security details, and setup provides funding/export steps. This goes well beyond the schema's minimal 'Which wallet operation to perform.'

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: 'Manage local x402 wallet — create keypair, check status, and get funding guidance.' It clearly distinguishes from sibling tools (token4u_chat, token4u_consumption) by focusing solely on wallet operations and explicitly noting this is for external x402 mode without a token4u account.

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 clear usage context: it is for 'pure external x402 mode' and notes 'No token4u account or internal wallet required,' which implies when to use this tool over alternatives that might require an account. However, it does not explicitly state when not to use it or name alternative tools.

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