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

Annotations already declare readOnly, idempotent, and closed-world, so the safety profile is covered. The description adds genuinely new behavior: the call fails when multiple EVM wallets exist and no address is supplied, and the response is raw JSON rather than a normalized shape.

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 what the tool returns and followed by the one conditional the caller must know. No filler, though the closing note about raw JSON is minor housekeeping.

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?

For a single-optional-parameter read tool with no output schema, the description covers source, keying, the conditional requirement, the failure mode, and the raw return format. Only the practical mapping from a wallet to the 'keyed by exchange' result is left implicit.

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% and the schema description already states that address is required when the account has several EVM wallets, so the description largely restates it while adding the consequence (backend rejection). No extra syntax, format, or default details are added, 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 resource and source: balances and positions from CEX exchange accounts linked to Hey Anon, with Hyperliquid as a concrete example. The 'exchange accounts' framing implicitly separates it from portfolio_defi and portfolio_tokens, though no sibling is named explicitly.

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?

Provides a conditional prerequisite (pass address when the user has several EVM wallets, or the backend rejects the call), which is useful operational guidance. However, it never says when to prefer this tool over portfolio_defi, portfolio_tokens, or portfolio_transactions, so the selection guidance is only implied.

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