Get eToro balances

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description usefully adds that balances are aggregated in a display currency and that the tool reports the account the key belongs to (not environment-specific), which is real context beyond annotations, but it says nothing about response shape or currency-conversion behavior.

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 compact sentences with the core purpose front-loaded and no filler. Slightly terse given the tool's scope, 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 zero-required-parameter read tool with annotations covering safety, the description is adequate on purpose but incomplete: it omits the meaning of unfiltered calls (all account types?), pagination, and the shape of the aggregated result. With no output schema present, a bit more disclosure would help.

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 only 50%: accountTypes and displayCurrency are documented, while includeSubAccounts and includeZeroBalances have no description in either the schema or the description. The description mentions no parameter at all, so it fails to compensate for the coverage gap.

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 verb+resource ('aggregated balances across the user's eToro accounts') and clarifies scope with 'trading, cash, ...'. It hints at differentiation from portfolio siblings via 'Not environment-specific', but never names a sibling like etoro_get_portfolio, so an agent must still infer the boundary.

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?

There is no explicit when-to-use guidance and no named alternative among the many portfolio/PnL siblings. The only routing clue is the negative statement that it is not environment-specific, which does not tell the agent when to prefer this over etoro_get_portfolio or etoro_get_portfolio_breakdown.

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