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

Annotations already establish readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: the result is comparative ('compared with the same holdings currency-hedged') and depends on the base currency setting, helping the agent interpret the output correctly. No contradiction with 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?

The description is two sentences and front-loads the core question, then adds the comparative detail and the base-currency precondition. Each sentence earns its place, though the wording is dense and the title adds little structure.

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 a full input schema and an output schema present, the description correctly focuses on semantics rather than syntax. It covers the essential purpose and the one non-obvious precondition, so an agent has enough to call the tool correctly, even if more detail on rate assumptions or edge cases could help.

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?

Schema coverage is 100%, so the baseline is 3, but the description adds meaning beyond the schema by explaining that `base` must be the reader's currency for the result to be meaningful. The `holdings` parameter is well documented in the schema, so the description does not need to repeat that detail.

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 states a specific analytical outcome: how much of the portfolio is priced outside the base currency and what exchange-rate moves added to growth, volatility, and worst fall versus a currency-hedged version. This goes well beyond a vague label, though it does not explicitly differentiate itself from sibling tools like portfolio_structure or measure_portfolio.

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 a clear precondition: 'Needs `base` set to the reader's currency to mean anything,' which tells the agent when the output is actually meaningful. It does not explicitly state when to prefer this tool over alternatives or when not to use it, so some usage guidance is left implicit.

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