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

With no annotations, the description carries the full burden. It does disclose real behavior — Solana verification by signature or reference scan, Ethereum by tx_hash after confirmations, and the conditional outcome of receiving a signed credit token when paid — but says nothing about auth requirements, behavior when unpaid, retry/idempotency, or error states.

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?

A single dense sentence, front-loaded with the action and the chain-specific branching in parentheses. Nothing is redundant, though the parenthetical packs several distinct behaviors into one clause.

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 7-parameter, 5-required cross-chain tool with no output schema and no annotations, the description covers the verification paths and the returned credit token but omits what pack/order_token/expires_at mean and what the agent should expect on failure or partial payment.

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 only 29%, so the description must compensate. It clarifies signature (Solana) and tx_hash (Ethereum) and ties them to the chain enum, but three required parameters (pack, order_token, expires_at) and order_id receive no explanation anywhere, leaving half the surface undocumented.

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 (check/verify) and resource (an order's USDC payment on-chain), and splits behavior by chain (Solana vs Ethereum). An agent can distinguish it from build_usdc_solana_tx (builds the tx) and create_usdc_order (creates the order) without opening any schema, though it never names those siblings explicitly.

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 is implied rather than stated: the chain-specific verification paths and the 'after confirmations' condition for Ethereum hint at when it applies, but there is no explicit when-to-use/when-not or pointer to alternatives such as create_usdc_order or build_usdc_solana_tx.

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