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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds genuinely useful behavior: each balance is sourced from the lane the collateral settles on, distinguishing committed ledger balances from onchain ERC-20 balanceOf, and that values are raw integer strings requiring 10^decimals scaling. It doesn't cover auth needs or rate limits, so not a 5.

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?

Three sentences that are front-loaded with scope, then the data-source explanation, then the format caveat; each earns its place. The middle clause is dense but not padding.

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 and annotations cover the safety profile, so the description only needs to carry the sourcing and formatting context, which it does. Nothing an agent needs to call 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%, so the chainId, include, and walletAddress descriptions already carry the semantics and the baseline is 3. The description restates the include behavior but adds no parameter-level detail the schema lacks (the decimals note describes output values, not parameters).

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 (get) and resource (collateral balances) scoped to a wallet, and clarifies the PM-default vs include=all scope. It never names a sibling like get_positions or list_collateral, so the agent gets no explicit routing signal, keeping it short of a 5.

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 description explains the default/all semantics and that chainId is needed only when multiple chains are active, which implies usage context. It gives no when-not guidance and doesn't contrast with get_positions or list_collateral, so usage is only implied.

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