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

The description goes well beyond the readOnlyHint annotation. It explains monetary units, per-unit vs. blended totals, the relationship between costBasis and avgCostPerUnit, the fallback meaning of purchasePrice, and the exact condition under which pnl is null. This meaningfully helps the agent interpret the response.

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 dense but every clause earns its place: it front-loads the purpose, then adds high-value monetary-unit and costing clarifications. It does not repeat schema contents or waste tokens.

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?

With no output schema, the description carries the burden of explaining what the response will contain and how to interpret it. It covers the key numeric fields, currencies, units, per-unit vs. total quantities, and the pnl null edge case. The single optional input parameter is already fully covered by the schema, making this sufficiently complete.

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 only parameter, type, is already fully documented in the schema with an enum list and description that says to omit it to return all asset types. Since schema_description_coverage is 100%, the description adds no additional parameter-level meaning beyond what the schema already gives, so the baseline of 3 is appropriate.

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 states a specific verb and resource: it lists the user's assets with quantity, purchase price, valuation, and P&L. It is distinct from the propose_* write tools by nature, though it does not explicitly contrast itself with get_net_worth even though that sibling is close in name and scope.

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 clear context for when to use the tool: when asset-level holdings and performance numbers are needed, and it notes the optional type filter. It does not explicitly explain when to prefer get_net_worth or when to avoid this tool, but the intended use is strongly implied by the detailed field guidance.

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