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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so safety is covered structurally. The description's contribution is limited to noting the results are 'currently open' (live state, not historical) and scoped to linked accounts; it says nothing about staleness, ordering, or empty-result 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 resource and the live-state qualifier front-loaded, followed by the safety profile and the optional filter. No filler.

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 one-optional-parameter read tool with annotations covering safety and no output schema, the essentials are present. The gaps are minor: what a 'position' contains and whether omitting account_id aggregates across all linked accounts.

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 0% for the single parameter, so the description must carry it, and it does confirm account_id is optional and that it selects an account. It adds no format, default, or behavior when the value is omitted (are all accounts returned?) or what happens with an unknown account_id.

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?

A specific verb and resource ('List currently open positions') with the scope 'on your linked trading accounts', which distinguishes it from the account-management sibling get_trading_accounts. It stops short of naming a sibling alternative 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?

'Optionally select account_id' implies the when-to-narrow case, but the description gives no explicit guidance on when to call this versus get_trading_accounts or get_trade_history, and states no prerequisites (e.g. needing a linked account).

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