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

Beyond the annotations, the description discloses that counts and last-activity cover only outgoing transactions, that inbound transfers are excluded, and that the full archive supports wallets of any age. It also adds pricing and auth expectations. These details materially shape what the agent should expect from results, and nothing contradicts the readOnly or idempotent hints.

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 and front-loaded with the output list before operational details. There is some redundancy between the opening summary and the restated metric list, but each sentence earns its place, including the pricing and header requirements that affect callability.

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 tool with a single required parameter and an existing output schema, the description is complete: outputs, metric semantics, chain scope, use case, and pricing/auth are all covered. No information needed to select or invoke the tool 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?

Schema coverage is 100%, so the baseline is 3; the description adds meaningful chain context by specifying 'any Base address,' which the bare schema label 'Wallet address' does not convey. It also reinforces that address is the only required input, though it stops short of providing format or validation details.

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 opens with concrete outputs: tx count, first/last activity, wallet age in days, and outgoing transaction count, all scoped to 'any Base address.' The 'read straight from the Base archive, not a 30-day feed' caveat clearly distinguishes it from indexer-style siblings like wallet_activity. There is no ambiguity about what resource the tool summarizes.

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 states it is 'Built for sybil screening and counterparty trust checks,' giving the agent a clear intended use case. It also implies when it beats lighter-weight alternatives by emphasizing full archive history rather than a 30-day feed, but it does not explicitly name alternatives or say when not to use it.

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