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

Annotations already declare readOnlyHint=true and destructiveHint=false; the description adds useful behavioral context beyond them by restricting to v4, explaining that omitting chainId covers every v4 chain, and telling the agent the response includes 'chainsCovered.' There is no contradiction with annotations.

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?

Four sentences with no filler. Scope, output content, use cases, alternative routing, boundary, and optional-parameter behavior are all front-loaded, and every sentence adds distinct value.

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?

Even without an output schema, the description names the substantive response components: supplied/borrowed amounts, per-chain rates, best-rate summary, and chainsCovered. It also explains exactly how to invoke the tool, covering selection and behavior well enough for an agent 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 coverage is 100%, so the baseline is 3; the description earns extra credit by explaining the practical behavior of omitting chainId ('cover every chain v4 serves') and reinforcing that version only accepts v4. This complements rather than merely repeats the schema.

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 states a specific verb and resource: 'One asset across every v4 chain at once, by symbol,' and enumerates the outputs (supplied, borrowed, rates, best supply/borrow summary). This clearly distinguishes it from asset-level versus wallet-level tools like get_wallet_balances and per-chain tools like get_markets.

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?

It explicitly names the use cases ('where should I supply USDC' and 'is this cheaper to borrow somewhere else'), calls out get_markets as the alternative requiring per-chain calls, and states the boundary: 'It answers about the asset, not about a wallet.' This gives an agent clear selection criteria.

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