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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, and the description goes well beyond them: max 32 KB payload, 60 RPM rate limit, stateless edge call, L402 pricing (20 sats), '?demo=true' bypass, and HTTP 400 on invalid input. These operational traits are exactly what an agent needs before calling an edge endpoint; the only gap is that index/latency behavior is left to the output schema.

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 tight sentences ordered purpose → when/alternative → operational limits, with zero filler. The final sentence is dense (size, rate, payment, error code all crammed into one clause chain) and could be split for scanability, which keeps it from a 5.

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 2-parameter stateless lookup with an output schema and full annotation coverage, the description supplies everything else an agent needs: what it detects, when to call it, the alternative, resource limits, payment model, and failure behavior. Nothing material 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 description coverage is 100%, so both parameters are already documented with enum values and defaults. The description restates that 'address_standard' defaults to 'auto_detect' and surfaces an out-of-schema '?demo=true' flag, but adds no format or validation syntax beyond the schema. Baseline 3 is correct when the schema does the heavy lifting.

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 first sentence states a specific verb and resource (compares a recipient wallet address against recent transaction history) and names the two exact threat classes it detects: vanity prefix/suffix lookalike spoofing and zero-value dusting. It also names the sibling tool it is not (simulate_evm_transaction_calldata), so an agent can route without opening either schema.

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?

Explicit trigger: 'Use when verifying a recipient EVM or Solana wallet address before sending funds.' It provides an exclusion plus a concrete alternative ('for decoding hex smart contract calldata payloads, use simulate_evm_transaction_calldata instead'), leaving nothing to inference.

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