Check Prepaid USDC Credit Balance & Deposit Instructions (Free)

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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the safety profile is covered. The description adds genuinely new context: the tool is free to call, it reads on-chain Base USDC data, and it serves two distinct modes depending on input. It stops short of describing response shape or latency, but that is a minor gap given the annotation coverage.

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?

A single front-loaded sentence that leads with the free/no-cost property and then explains both modes. Slightly redundant phrasing ("100% free utility tool with zero cost" says the same thing twice) keeps it from a perfect score.

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?

With no output schema and one optional parameter, the description covers what an agent needs: cost, both return modes, and the input trigger for each. Pricing tier detail and response formatting are left unspecified but not essential for correct invocation.

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 100% and already documents the optional txHash as a 66-char 0x string. The description adds the key semantics the schema omits: omitting txHash switches the tool to deposit-address/pricing mode, which is essential branching behavior not expressed in the schema.

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?

States a specific verb and resource — checking remaining prepaid USDC credit balance and call count — and additionally names the alternate behavior (returning a deposit address and pricing tiers). The domain is clearly distinct from the sibling tools, which are token/alpha/security lookups, so an agent can route without ambiguity.

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?

Gives clear context for when to call it: verifying a Base USDC tx hash for credit balance, or fetching deposit/pricing info to upgrade beyond the 3 free daily calls. It does not explicitly state when NOT to use it or name an alternative tool, but the conditional (with vs. without txHash) functions as practical usage guidance.

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