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

With no annotations, the description carries the whole burden. It does disclose a real behavioral trait — the account is auto-created by the first trade, so a call may return an empty/not-yet-opened account — and implicitly frames this as a read of one's own account. It says nothing about permissions, whether the token is session state, or failure behavior for an invalid token.

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?

Two short sentences, front-loaded with the resource and its returned fields, with the lifecycle fact placed last. The parenthetical is slightly awkward but nothing is wasted.

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-parameter read with no output schema and no annotations, the description covers identity (wallet token), content (cash, holdings, value, weekly return), and lifecycle (opened by first trade). Only the invalid/missing-token behavior is left unstated, which is a minor gap at this complexity.

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% for the single optional 'token' parameter, so the schema already explains it. The description restates it as '(wallet token)', which reinforces that it identifies the caller's wallet but adds no format, sourcing, or omission behavior (e.g., what happens if the token is left out).

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 the resource (paper Exchange account reached with a wallet token) and enumerates what it yields: paper cash, holdings, value, and weekly return. That is enough to tell it apart from exchange_trade (which acts) and exchange_table (which likely shows market state), though the verb itself is implicit rather than stated.

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: the parenthetical '(wallet token)' hints that a token is needed, and 'Your first trade opens the account' tells the agent the account may not exist until trading. There is no explicit statement of when to call this versus sibling tools like 'me', 'exchange_table', or 'exchange_winners'.

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