International Valuation

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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, and the description adds substantive behavior beyond them: pure arithmetic with no I/O or external calls, results rounded to 2 decimals, no auth or rate limits, and precise error semantics for unknown methods or missing required parameters. That error contract is the key operational detail an agent needs.

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?

Front-loaded with purpose, then usage, then the method-to-parameter mapping, then return/behavioral notes. Dense but almost every sentence carries a distinct constraint. Minor penalty for run-on sentences with heavy parentheticals that make it slightly harder to scan.

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, yet the description still briefly names the return fields (value, method, inputs, assumptions, chapter, formula_number, steps), which is harmless and mildly helpful. Combined with the error contract and parameter mapping, an agent has everything required to invoke this 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?

Schema coverage is 100% and the enum already embeds the formulas, so the baseline is 3. The description earns extra credit by mapping each method to its required parameter set (ppp→spot_rate+inflation_foreign+inflation_domestic, etc.) and clarifying that only 'method' is required while the rest are method-dependent — a cross-parameter constraint the schema cannot express. It falls short of 5 only because per-parameter semantics are largely left to the schema.

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 domain (cross-border adjustments) and enumerates the three concrete methods (PPP, country risk premium, international CAPM), and explicitly distinguishes itself from the sibling valuation_capm. An agent can route between this and the domestic cost-of-equity tool without opening either schema.

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?

Gives explicit when-to-use ('Use for cross-border cash flows and country risk'), when-not ('Not for the domestic cost of equity — for that use valuation_capm'), and companion tools ('pair with valuation_capm and valuation_time_value'). This is exactly the routing guidance needed in a 14-sibling family.

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