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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuinely new behavior: nulls mean the wallet isn't set up, a 404 means no agent wallet yet (setup is in the app), view=agent_wallet re-checks approval against Hyperliquid at call time, and the tool never returns keys. That is exactly the error/null/auth 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?

Front-loaded with the core purpose, then scannable per-view sentences; nearly every clause carries information. Minor deductions for a long run-on opening sentence and the fragmentary trailing 'The response carries app_url, Settings → Addresses.'

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 fully specifies the return shape per view (identity fields, agent_wallet record plus created_at/is_rotation, balances and perps account, account mode) along with null and 404 semantics. An agent has everything needed to call and interpret it.

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 0%, so the description carries the full burden — and it does, defining all four enum values, the default, and what each returns. No parameter is left ambiguous.

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 scope ('YOUR wallets and the agent's approval state') and enumerates what each view returns, so the agent knows exactly what comes back. It does not explicitly distinguish itself from near-siblings like get_account_balances or whoami, which is the only thing keeping it from a 5.

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?

Documents each view value (identity, agent_wallet, balance, account_mode) with enough detail that an agent can pick the right one, and labels identity as the default. It does not name alternative tools for overlapping needs (e.g., account balances elsewhere), so it stops short of explicit when-not guidance.

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