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

Annotations already declare readOnlyHint and openWorldHint, but the description adds valuable context beyond that: it states the tool is paid ($0.001, x402), specifies the data source (on-chain DEX pools), and details chain/token coverage and limitations (EVM vs Solana, up to 20 extra tokens). This helps the agent understand cost and data freshness, though it does not mention rate limits or authentication requirements.

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 description is front-loaded with the core purpose and then concisely details coverage, pricing, and data sources. It uses semicolons to pack multiple facts efficiently, though the single long sentence could be slightly split for readability. Every sentence contributes useful information.

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 four parameters, no output schema, and annotations that cover read-only and open-world aspects, the description is fairly complete: it explains what data is returned (balances, holdings, USD values, totals), data sources, cost, and chain/token coverage. It does not elaborate on the min_usd parameter or response format, but those are either covered by the schema or not critical for invocation.

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 all four parameters fully. The description reiterates some details (e.g., 'up to 20 tokens you pass', chain list) but adds no new syntax or semantics beyond what the schema provides, so a baseline 3 is appropriate.

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 clearly states the tool's purpose: retrieving a multi-chain wallet portfolio with native balances, token holdings, USD values, and per-chain totals. It specifies the scope (EVM vs Solana chains, token coverage) but does not explicitly differentiate from sibling tools like wallet_report or token_report, leaving the agent to infer the distinction.

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 provides no guidance on when to use this tool versus alternatives. It describes what the tool does but does not mention conditions for use, exclusions, or sibling tools, so the agent must infer usage from the purpose alone.

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