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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds meaningful context beyond that: the fee schedule is volatile ('may change'), it is the authoritative source to consult before payment, and passing wallet_address changes the returned payload. It omits auth needs and rate limits, so not 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?

Front-loads purpose, then usage, then a structured Returns list with zero filler. The Returns breakdown is useful but partially redundant since an output schema exists, which keeps it from a perfect score.

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 payment-gating tool, the description covers the key facts an agent needs: when to call it, that values are dynamic, the optional wallet_address effect, and a summary of the returned fields. Combined with the output schema and annotations, nothing critical 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% and the single parameter's description already explains that wallet_address checks free_escrows_remaining. The description restates this effect ('Pass wallet_address to see how many free escrows remain') with no additional syntax or format detail, so the baseline 3 applies.

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 (Return) plus the resource (fee schedule) and enumerates what it contains: audit fee, accepted assets, free-tier rules, escrow limits. An agent can distinguish it from siblings like get_xrp_price or get_rlusd_quote, which return prices rather than the fee/payment policy.

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?

Explicitly states when to call it — 'Call this before calling any paid endpoint' — and warns against hard-coding amounts. However, it does not name when-not to use it or point to any alternative tool for fee-related questions, so it falls just short of the 5 bar.

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