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

Beyond the readOnlyHint and idempotentHint annotations, the description discloses important behavioral traits: no transfer, no per-account event, and nothing in tx history, plus explicit flagging of downward moves. It also covers auth and rate-limit context (x-credit-token header, free tier), which annotations do not provide.

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 key differentiation is front-loaded with the striking first sentence, and pricing/auth details are confined to the end. The description is slightly wordy with its em-dash framing, but each sentence contributes distinct, useful 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 single-address read-only history tool, the description covers input, alternative tool, behavioral semantics, use case, pricing, and access constraints. Since an output schema exists, omitting return-field details is acceptable.

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?

The schema already documents the only parameter at 100% coverage with 'B20 Asset token address'. The description merely repeats 'Required input: address' without adding format, validation, or examples, so the 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?

The description opens with a distinctive value proposition ('Every silent balance rescaling this token ever did') and states a concrete action: replay the full MultiplierUpdated history and flag downward moves. It also contrasts with b20_rebase, making the tool's purpose unambiguous.

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?

It explicitly names the sibling b20_rebase as the tool for today's value ('b20-rebase shows today's value; this replays...'), giving an agent a clear selection rule. It also provides the intended context ('before you hold a rebasing RWA') and access prerequisites like address, pricing, and no wallet/API key.

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