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 the details that matter beyond them: pricing ($0.04/call over x402 on Base), the prepaid x-credit-token header for unlimited calls, no free tier, and no API key requirement. It also discloses the domain behavior (Coinbase settling splits/dividends via multiplier) so the agent understands why two numbers are returned.

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-loaded with the core question and the key differentiator, and every section carries content (mechanism, scope, pricing, auth). It is somewhat long and the multiplier rationale is slightly repetitive, but no sentence is pure filler.

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 no elaboration, and the description still covers everything an agent needs to invoke correctly: required input, the meaning of the two returned numbers, scope exclusions, payment/auth model, and cost. Nothing material 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?

One parameter with 100% schema coverage, so the schema already documents 'wallet' fully. The description only restates that wallet is required, adding no format, chain, or validation nuance 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?

States a specific verb+resource (returns both the unadjusted and multiplier-adjusted share count per tokenized-stock holding for a wallet) and the exact mechanism that makes it distinct: B20 Asset tokens do not apply multiplier() to balanceOf(). An agent can tell this apart from generic balance readers like token_balance or wallet_tokens without opening any 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?

Gives clear usage context and an explicit scope exclusion ('Wallet balances only; LP/lending is declared excluded, never zeroed'), which tells the agent when this result is and is not authoritative. It stops short of naming the alternative tool to use for raw balances, so it is clear context without explicit alternatives.

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