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

Annotations already mark the tool as read-only and idempotent. The description adds useful behavioral context: it is scoped to ~48h of Base blocks, covers both sent and received USDC transfers, and is preflighted so the user never pays during an RPC outage. This goes beyond what the annotations provide.

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 tight sentences with no filler. It front-loads the core purpose and data returned, then adds the preflight benefit. Everything included earns its place.

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 one-parameter, read-only tool with an output schema present, the description is complete: it specifies the asset, network, time window, data shape, and a cost/outage safeguard. Nothing needed for correct invocation 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?

The schema provides 100% coverage for the single address parameter, including the 0x-prefix format requirement. The description does not add parameter-specific detail beyond what the schema already states, so the baseline of 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 states exactly what the tool does: it returns USDC transfers sent and received by an address over the last ~48h of Base blocks, including counts, volumes, and sample transaction hashes. This specific scope clearly distinguishes it from generic siblings like tx_activity or balance_check.

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 intended use case is clear: performing an on-chain counterparty check for USDC settlement activity on Base. It does not explicitly name alternative tools or give when-not-to-use guidance, but the asset and time-window scoping is strong enough for an agent to infer appropriate usage.

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