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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds real behavioral context on top: spam tokens lacking a price are silently dropped (affecting result counts), and each call costs $0.005 USDC via x402, which is a payment precondition the annotations do not 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?

Three short sentences, front-loaded with the core noun phrase and each carrying distinct information (contents, filtering rule, cost). The first sentence is clause-dense but readable, and nothing is redundant with the schema.

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 no output schema, the description correctly carries the return-value burden by describing the token/price/per-chain/total structure. Combined with the annotations and the disclosed payment model, an agent has what it needs to call this correctly; only error and rate-limit behavior are unaddressed, which is minor for a read tool.

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 the schema already documents both parameters, making 3 the baseline. The description contributes only marginally: it restates the supported chain list and adds '(or Solana)', which the schema's networks field notably omits, but it gives no syntax, default, or all-chains-vs-subset behavior for the optional networks parameter.

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 names a concrete resource (multi-chain wallet portfolio) and enumerates exactly what comes back: every token held on Ethereum, Base, Arbitrum, Optimism, Polygon or Solana, with live USD prices, per-token value, per-chain value, and the total. That content scope cleanly separates it from neighbors like wallet_nfts, wallet_watch, solana_wallet, and token_holders without needing to name them.

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 only implied by the scope: an agent can infer this is the tool for valuing a whole wallet rather than a single token or NFT set. There is no explicit when-to-use statement, no exclusion, and no named alternative (e.g. wallet vs. report_wallet) to route between when several wallet tools could apply.

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