NanoParse

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

Annotations declare readOnly/openWorld/non-idempotent/non-destructive, and the description adds everything an agent actually needs on top: $0.005 per page read, 10 free parses per month with no key, cloud-host wallet attestation via plain EIP-191 with no payment, and the crucial guarantee that unreadable pages (bot wall, consent wall, paywall, PDF) return a named reason and are never charged. The per-call billing also implicitly explains the non-idempotent hint, since a retry costs another page.

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 correctly — what it does, what it costs, then the auth and payment mechanics — and most sentences carry distinct operational facts. It is longer than ideal, with mild redundancy between the free-tier sentence and the cloud-host wallet-claim sentence, plus a marketing-ish 'no minimum, no commitment, no balance to spend down' clause that could be cut.

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 paid, auth-gated, open-world fetch tool with 100% schema coverage and an output schema handling return shape, the description covers every decision point an agent faces: cost, free allowance, host-dependent auth, batching strategy, failure-mode billing, and the full x402 retry loop. Nothing needed to call it 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 all four parameters are self-documenting and the baseline is 3. The description earns an increment by giving the sequencing the schema cannot: payment_signature is normally obtained by reading payment_terms out of a payment_required error response, and wallet_address/wallet_signature are a one-time claim rather than per-call.

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 ('Read one URL into clean Markdown with Litmus signals') and immediately bounds the scope by contrasting it with site-wide or list reads, which must loop one URL per call. An agent knows exactly what unit of work this performs, and the name plus that scope statement distinguish it from the status sibling 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 explicit invocation routing: use wallet_address + wallet_signature on cloud hosts to claim the free tier, pay on the first call if price and payTo are known, otherwise sign the payment_terms from the returned payment_required error and retry. It does not mention when to consult the nanoparse_status sibling, so the alternative-selection guidance is strong on the payment path but incomplete on the sibling path.

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

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

Annotations already establish readOnly, idempotent, non-destructive, open-world behavior, so the bar is lower. The description adds real value by framing this as a predictive pre-flight check (will the next call succeed without payment) rather than a plain status read, though it says nothing about auth requirements, caching, or staleness of the quota reading.

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?

Two tight sentences, no filler, with the enumeration of what is checked front-loaded ahead of the usage directive. Every clause carries information.

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?

Output schema exists, so return fields need not be re-explained, and annotations cover the safety profile. The one real gap is the optional 0-required-parameter address: the description never clarifies whether omitting it falls back to a configured/default wallet.

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% for the single address parameter, so the schema already documents it fully. The description adds no address-format or default-behavior detail — notably it never explains what happens when address is omitted, which the schema marks as not required.

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?

Specific verb (check) plus concrete resources (wallet balance, USDC balance, quota state) and a forward-looking outcome (whether the next /fetch will succeed without payment). Naming the /fetch call explicitly separates it from the sibling nanoparse_fetch.

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?

"Use before spending" gives a clear situational trigger and the reason (to know how much to fund). It stops short of stating when not to call it or contrasting the cost of calling it vs. skipping, but the pre-flight role is unambiguous.

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