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

Beyond the readOnlyHint/openWorldHint annotations, the description discloses the pricing model ($0.002 USDC per successful call via x402 on Base, Solana or Arc, failed calls not charged) and the shape of the aggregation. That pricing/charge semantics is genuinely additive context annotations cannot convey.

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?

A single dense sentence is front-loaded with purpose and coverage, then return structure, then pricing — every clause carries information. It is long, but nothing is purely redundant; slight trimming of the enumerated position types would help.

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?

Given an output schema exists, the description needn't enumerate return fields, yet it still summarizes the aggregation and debt totals. Combined with disclosed pricing, chain coverage and annotations, an agent has everything needed to call it correctly.

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 both parameters are already documented (address format, limit range). The description reinforces that positions are returned but adds no new syntax or default detail, 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?

States a specific verb+resource ('multi-chain wallet net worth with DeFi positions and debt') plus concrete scope (40+ EVM chains and Solana, Zerion API) and the exact breakdown returned. This clearly distinguishes it from sibling balance tools like crypto_zapper_token_balances or crypto_solscan_account_tokens.

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 the scope (value an address's holdings and DeFi positions), but there is no explicit when-to-use/when-not and no sibling alternative named as a routing alternative. An agent must infer that this is the portfolio-valuation tool versus token-balance siblings.

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