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

Annotations already declare readOnlyHint/idempotentHint/non-destructive and openWorld, so the safety profile is covered. The description adds genuinely useful non-annotation behavior: pricing ($0.08/call over x402 on Base), the prepaid x-credit-token header for unlimited calls, no free tier, and no API key requirement.

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 dense with useful contract details. However, the opening redundantly repeats 'up to 5 B20 tokens' twice in the first sentence, wasting space in an otherwise tight definition.

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?

Payment/auth behavior, batch limit, and the scored dimensions are all disclosed, and an output schema exists so return format needn't be explained. Nearly complete for an agent to call it correctly, with only the sibling relationship left implicit.

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%, so the single 'addresses' parameter is fully documented as comma-separated B20 addresses. The description reinforces it as required and adds the 'up to 5' cap not present in the schema, but adds little else beyond the baseline.

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+resource ('Freeze/seize scan for up to 5 B20 tokens') and enumerates the safety dimensions scored (freeze/seize/pause/rebase/uncapped-mint). It implicitly distinguishes itself from single-token siblings like b20_safety via the explicit 'up to 5' batch scope, but never names the alternative, keeping it short of a 5.

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?

'For portfolio holders and agents screening several B20s at once' gives clear context that selects this tool over the single-token variant. It does not, however, state any exclusions or point explicitly at the single-token alternative for one-off checks.

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