get_portfolio_overview

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

Beyond the annotations (readOnly, openWorld, idempotent, non-destructive), the description discloses crucial behavioral quirks: price/value are derived from average price and theoretical gain because Darwin doesn't report current price; bonds (M. symbols) are quoted as percentage of nominal; and the tool performs internal reconciliation with the reported figures. It further instructs the agent to handle reconciliation.false by saying so and quoting the residual, which is rich, actionable transparency.

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?

The description is well-structured and front-loaded: a one-sentence value proposition, followed by a specific usage recommendation, then necessary caveats about data derivation and reconciliation. Every sentence earns its place; the warnings about bonds and reconciliation are critical for correct use and are not redundant with the schema or annotations.

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?

Given the tool has no parameters and an output schema exists, the description doesn't need to document return values. It covers the full behavioral surface: the scope of data returned, the derivation quirks, the bond scaling issue, and how to handle reconciliation failures. It also positions the tool relative to siblings, making it complete for an agent to select and invoke correctly.

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 has zero parameters, so schema coverage is trivially 100%. Per the baseline for zero-parameter tools, the description doesn't need to add parameter semantics, and indeed it doesn't attempt to. It slightly exceeds the baseline by clarifying the tool's scope, but there is no parameter-specific information to add.

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 opens with a clear, specific verb-resource pair: 'The whole picture in one call: every position with its current price and value, plus portfolio totals and P&L.' It explicitly distinguishes itself from the sibling tool get_positions by stating when to prefer it, making its purpose unambiguous.

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 gives explicit when-to-use guidance: 'Prefer this over get_positions when the question is about how the portfolio is doing or what it is worth.' It also provides a strong negative guideline: 'Do not compute values yourself from get_positions' with a concrete reason about bonds, which helps the agent avoid a known pitfall.

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