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

Goes well beyond the readOnlyHint annotation by disclosing the paid nature of the call ($0.01 USDC), the settlement network (Solana mainnet), and the challenge-then-pay protocol. It does not cover failure modes (expired signature, insufficient payment) or latency, keeping it short of a 5.

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 sentences, zero filler, and correctly front-loaded: the value proposition and unit of measurement come before the payment mechanics. Every clause carries information an agent needs.

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 read-only tool with no output schema, the description sketches the return content (price and bps deviation) and fully explains the payment gate. Missing only failure/retry behavior if payment is not recognized.

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%, with payment_signature already fully documented in the schema, so the baseline is 3. The description adds the cost context and the ordering of the two calls but no new syntax or format detail for the parameters themselves.

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?

Names a specific resource and measurement: stablecoin peg status with live price and deviation in basis points from $1.00. It does not explicitly differentiate itself from siblings get_price or get_monitor_pegs, so an agent must infer the distinction from the 'peg/deviation' framing rather than being told.

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 an explicit two-step invocation sequence: first call without payment_signature yields the payment challenge, pay, then re-call with the signature. That is concrete when/how guidance for this tool's gating flow, but it never states when to prefer this over get_price or get_monitor_pegs.

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