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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, and the sentence 'This tool does not create, modify, or delete data' largely restates them. The description does add useful behavioral color about snapshot resolutions (daily/weekly/monthly) and aggregated USD values, but says nothing about rate limits, cost, partial failures, or what happens when wallets are invalid.

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?

It leads with a title restatement, then the endpoint, then a non-destructiveness line that duplicates annotations, then a feature summary sentence. The useful content (endpoint, batch semantics, snapshot resolutions) is present but diluted by redundant framing, and the sentence order meanders rather than front-loading the key distinction.

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 a full output schema and fully documented params, the core call is answerable. What's missing is the batch-vs-single decision against a very crowded sibling set and any note on limits/failure behavior for a 10-wallet batch — enough gaps that an agent could still pick the wrong sibling.

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 days, resolution, ownerAddresses (max 10) and vybeTokenFilter are already documented. The description only restates that the body lists wallets, adding no syntax, defaults, or interaction semantics beyond the schema — 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 states a specific verb and resource (fetch multi-wallet token balance history) and pins the exact endpoint POST /v4/wallets/batch/token-balances-ts. 'Batch' and 'multi-wallet' implicitly separate it from the single-wallet sibling get-wallet-token-balance-history, but that sibling is never named, so differentiation is left to inference.

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?

Usage is implied by 'lists wallets to read' and 'multi-wallet', suggesting this is the bulk variant, but there is no explicit statement of when to pick it over get-wallet-token-balance-history or get-token-balances-batch. No prerequisites or exclusions are given.

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