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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds material context beyond them: pricing ($0.10 per call over x402 on Base), the prepaid x-credit-token header for unlimited calls, no free tier, and no API key required — all actionable for an agent deciding whether it can call.

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?

The verdict-oriented purpose is front-loaded and every clause carries information (what it aggregates, the wallet flag, pricing/auth). It is dense and slightly run-on with parentheticals, but not padded.

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?

With an output schema present the description needn't explain the return payload, and annotations cover the safety profile; the description fills the remaining gaps (cost, payment header, required input). It is complete enough to call correctly, though sibling routing remains unaddressed.

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%, so both parameters are already documented in the schema. The description's 'Pass wallet= to also check if YOUR address is already blocked' and 'Required input: address' essentially restate the schema descriptions rather than adding syntax, format, or edge-case meaning. 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+resource: it produces a single GO/HOLD/STOP verdict for a Base-native B20 token, aggregating seize/freeze/rebase/pause/uncapped-mint checks. It also asserts a routing role ('The B20 tool to bind first'). It does not, however, distinguish itself from the many close siblings such as b20_guard, b20_safety, or b20_transfer_preflight, so the differentiation is asserted rather than demonstrated.

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?

Clear context for use: run it before touching/trading a B20 token, and pass wallet= to additionally check your own address's blocked status. It gives the condition that selects it (pre-trade on a B20) but never names an alternative tool or an exclusion, leaving the agent to guess against b20_guard/b20_safety.

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