cash_balance

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

Annotations already mark the tool read-only and non-destructive, and the description adds substantial behavioral context: the cash-vs-buying-power distinction, settlement endpoint failure semantics, the trading-session requirement, paper-mode local-ledger behavior, and the explicit warning that the endpoint is pending verification. This is far beyond what annotations provide.

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?

Despite its length, every sentence earns its place: core distinction, field meaning, settlement edge case, authentication, paper-mode exception, and verification status. The structure front-loads the main purpose and then layers caveats, making the complexity navigable.

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?

This is complete for a zero-parameter read tool: no invocation arguments are needed, and the description explains the meaning of results, failure conditions, authentication requirements, paper-mode behavior, and reliability status. Nothing an agent needs to call or interpret this tool correctly is missing.

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?

The input schema has zero parameters, so there is no parameter documentation burden. The description still enriches understanding of the returned fields (`cashIdr`, `buyingPowerIdr`, `settlement`), which is useful even though it is not parameter-level semantics.

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 clearly identifies the tool as returning the trading account's cash balance and buying power, and it distinguishes the two concepts with `cashIdr` vs `buyingPowerIdr`. It lacks an explicit verb like 'retrieves' or 'reads', but the resource and meaning are unmistakable.

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?

It gives concrete application guidance: use buying power to judge affordability, treat settlement absence with `settlementUnavailable` as a failed second request, and in paper mode read the local ledger rather than requiring a session. It does not name sibling tools as alternatives, but it states clear preconditions and exclusions.

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