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

With no annotations provided, the description carries the full burden. The verb 'Returns' clearly indicates a read-only operation with no side effects, which is sufficient for this simple tool. It does not discuss rate limits, data freshness, or error conditions, but those are not critical for a portfolio fetch.

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 entire description is a single, front-loaded sentence that conveys the tool's purpose without any filler. It efficiently lists all major output categories.

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 no output schema, the description compensates by enumerating the return contents (total value, cost basis, gain/loss, per-metal breakdown, individual holdings). This sufficiently outlines the response structure for an agent, though it omits format specifics like JSON or units.

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 schema already describes the only parameter (api_key) with 100% coverage, so the description adds no additional parameter semantics. Baseline 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 uses the specific verb 'Returns' and identifies the resource as 'your precious metals portfolio,' listing exact components (total value, cost basis, gain/loss, per-metal breakdown, individual holdings). This clearly distinguishes it from sibling tools like get_spot_prices or get_analytics.

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 use when portfolio data is needed, listing the exact data returned. However, it does not explicitly exclude alternatives or provide when-not-to-use guidance relative to the listed sibling tools, so it lacks explicit alternative comparison.

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