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

Annotations already establish the safe read-only profile, but the description adds genuinely useful non-structural context: per-call price ($0.05 over x402 on Base), the prepaid x-credit-token header for unlimited calls, no free tier, and no API key required. It also explains what counts as failure (the 'transfers brick' scenario). This is exactly the operational detail annotations cannot carry.

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 purpose and failure modes before cost/auth details, and most sentences earn their place. The opening fragment list and some emphatic phrasing ('transfers brick') are stylistic rather than strictly necessary, costing a small amount of signal-to-noise.

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?

An output schema exists, so return values need not be re-explained, yet the description goes further by summarizing the verdict taxonomy and the can-this-token-move flag. Combined with cost, auth, input, and audience coverage, an agent has everything needed to call and interpret it correctly.

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 documents the input fully. The description's 'Required input: address' merely restates this and adds no format or interpretation detail (e.g., chain qualifier). Baseline 3 for high-coverage schema is appropriate.

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?

Strong verb+resource: an 'audit'/'misconfiguration lint' of B20 policy scope config, with the specific failure modes enumerated (dangling bindings, ALWAYS_BLOCK, renounced lists, live pauses). It is distinguishable from general siblings like b20_safety or b20_freeze_check by scope, though it never names a sibling it is not.

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 clear usage context — 'pre-launch lint for issuers, stuck-funds guard for holders and merchants' — which tells the agent when this tool is appropriate. It stops short of naming alternatives or stating when-not to use it (e.g., versus b20_transfer_preflight or b20_freeze_check).

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