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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds genuinely non-structural facts: pricing at $0.03/call over x402 on Base, the prepaid x-credit-token header for unlimited calls, no free tier, and no API key required. It also discloses the output classification labels (heavy_dilution / active_minting / minor_minting / quiet), though it says nothing about window alignment or error behavior for unsupported addresses.

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 value proposition and the sibling differentiation are front-loaded, and the payment mechanics come after. It is dense and slightly stream-of-consciousness with em-dashes and a marketing hook, but almost every clause carries actionable information.

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 two-parameter read tool with an output schema, the description covers purpose, alternative, parameter range, payment/access model, and the classification vocabulary. Only edge-case behavior (invalid token, empty window) is unaddressed, which is a minor gap given the output schema carries return structure.

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 baseline is 3, but the description adds a constraint the schema lacks entirely: the valid range for days (1-90) alongside the default of 30. It adds little on address beyond 'Required input', which the schema's required array already conveys.

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 and resource ('every mint incl. batchMint in the window: amount, recipients, share of current supply') and explicitly contrasts itself with the sibling b20_supply ('shows the dilution ceiling; this shows the actual printing'). An agent can distinguish the two without opening either schema.

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?

Names one explicit alternative (b20_supply) and the condition that selects it, plus the intended audience ('agents holding B20 stablecoins and RWAs'). It does not state when not to use it or mention other adjacent siblings like b20_rebase_history or token_transfers, so it stops short of full routing guidance.

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