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

Annotations already declare readOnly/idempotent/openWorld, so the bar is lower, yet the description adds substantial context: data source (onchain role events), the exact roles read (mint/burn/seize-via-burnBlocked/pause/admin), what is reported (controllers, centralization, admin renounced), and pricing/auth terms ($0.05/call over x402, prepaid x-credit-token header for unlimited calls, no free tier, no API key).

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 the core question ('WHO can mint, seize, freeze or pause this B20?') then handles contrast, method, use case, and payment terms. Dense but every clause carries information; the pricing block is slightly heavy but material for callers.

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 described, and the description still covers the data source, the roles inspected, the reported outputs, the use case, and payment/auth mechanics. Nothing an agent needs to invoke it correctly 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% with a single self-documenting 'address' field. The description only restates 'Required input: address' without adding format, chain, or validation detail beyond the schema. Baseline 3 applies when the schema does the work.

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 (reads role-based access control / controllers of a B20 token) and explicitly contrasts with the sibling b20_safety: 'b20-safety tells you WHICH powers a B20 has; this tells you WHO holds them.' 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?

Provides a clear context for use ('The issuer-control map an agent needs before holding a regulated Base-native asset') and implicitly routes the WHICH-powers question to b20_safety. No explicit when-not condition, but the alternative is named and the standing use case is concrete.

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