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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the sentence 'This tool does not create, modify, or delete data' largely repeats structured data. It does add some value by describing the returned data categories and the endpoint path, but says nothing about auth, rate limits, or the max-10-wallet constraint beyond what the schema documents.

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 definition is short but front-loads a restatement of the title ('Token Balances (Batch)') and a redundant 'does not create, modify, or delete' clause that the annotations already cover. The final sentence is a dense run-on that mixes endpoint purpose with return-content detail. It is not bloated, but several sentences do not earn their place.

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 fully documented nested schema, output schema present, and safety annotations, the description covers the essentials for calling the tool. The remaining gaps are routing (no explicit sibling differentiation) and operational constraints (auth, rate limits), which keep it at minimum-viable rather than complete.

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% and every nested body property (ownerAddresses, limit, sortByAsc/Desc, filters) is documented in the schema. The description only restates that the body lists wallets, adding no filter, pagination, or sorting semantics beyond the schema. Baseline 3 is appropriate when the schema already 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 and resource: fetches multi-wallet token balances and names the exact endpoint (POST /v4/wallets/batch/token-balances), with scope details (SPL, Token-2022, USD values, staking, portfolio metrics). It distinguishes batch from single-wallet by describing 'multi-wallet' balance reads, though it never names the single-wallet sibling get-wallet-token-balances, so the differentiation is implicit rather than explicit.

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?

The word 'batch' and 'The request body lists wallets to read' imply when to use it — for multiple wallets at once — but the description gives no explicit 'use this when / use X instead' guidance. It does not point to the single-wallet get-wallet-token-balances sibling or to get-token-balance-history-batch, leaving the choice to inference.

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