get_balance

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the trailing 'Read-only' adds no credit-bearing information. The genuinely additive piece is '(paper by default)', which tells the agent which trading environment the balances come from and is not present in the annotations.

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 payload (holdings and account summary). The final 'Read-only.' is redundant with the annotations and could be cut, keeping it from a perfect score.

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?

An output schema exists, so return structure need not be described, and the annotations carry the safety profile. The description covers scope and environment adequately, though it omits latency/pagination-type behavior (likely irrelevant for a single account summary).

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 tool takes zero parameters, so there are no parameter semantics to document; the baseline for a no-arg tool is 4. The description correctly implies no filtering input is required.

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-derived outcome (holdings and account summary) for a specific resource (the configured KIS account), which clearly distinguishes it from the market-data siblings (get_quote, get_ohlcv, get_financials). It does not explicitly name or contrast an alternative, so it falls just short of 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?

The description implies usage (account-level aggregate data for the configured account) but never says when to call this versus the sibling lookups, nor states prerequisites. The 'paper by default' remark gives useful context but is not a when/when-not guideline.

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