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

Annotations cover read-only/idempotent/non-destructive, so the bar is lower, yet the description adds real operational context: a free-tier cap of 2 calls/day per IP and the exact fallback payment mechanisms (WorkSats crd_ token, L402 header, Base USDC x402TxHash). It also discloses a security constraint (never send private keys or seed phrases) and what fields the verification result contains.

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?

Front-loaded with the core action and address types, followed by a short safety line and a dense but useful payment sentence. Every sentence carries information, though the payment sentence packs three mechanisms and a rate limit together a bit tightly.

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, the description correctly lists what is returned (network, type, witness version, scriptPubKey hex). Combined with the address-format coverage, safety warning, and rate-limit/payment detail, an agent has everything needed to call this correctly, including on the paid path.

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 baseline is 3; the description still adds value by grouping the payment parameters into a coherent narrative (crd_ token vs. L402 header vs. x402TxHash) and by framing network as an expected-value check. It notably mentions an L402 header that isn't a schema parameter, which helps an agent understand the full payment surface.

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 (verify a Bitcoin address) and enumerates the address encodings/script types it handles (Bech32m P2TR, Bech32 P2WPKH/P2WSH, Base58 P2PKH/P2SH), plus the concrete outputs (network, type, witness version, scriptPubKey hex). An agent can immediately distinguish this from check_descriptor and check_psbt, which operate on different artifacts.

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?

Usage context is clear: this is the tool for validating an address string, with a safety boundary about never submitting secrets. It also explains the payment path once the free tier is exhausted. It stops short of explicitly saying when not to use it or naming sibling alternatives for descriptor/PSBT work, so a 4 rather than 5.

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