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

While annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, the description adds critical behavioral details: it fails closed without amounts if rates are not complete/valid/fresh/date-stamped, and it explicitly disclaims generating any payment-plan-related outputs. This goes beyond what annotations provide.

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 three sentences: first disarms the legacy name, second states the core function and condition, third eliminates common misconceptions. Every sentence earns its place, and the main purpose is front-loaded.

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's simplicity (two parameters, full schema descriptions, output schema present, and strong annotations), the description adequately covers what the tool does, under what conditions it works, and what it does not do. No critical selection-relevant information is missing.

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 input schema has 100% description coverage, including clear descriptions for both 'price' and 'currency.' The tool description restates the scope (asking-price amount, not deposit) but adds no new parameter-level information beyond the schema. The schema already carries the burden, so a 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 explicitly states that the tool converts an entered property asking-price amount across GBP/EUR/USD/TRY, with the title reinforcing 'Currency Conversion Only.' It also distinguishes itself by listing what it does not do (payment plan, deposit schedule, etc.), making its purpose unmistakable.

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 clearly presents the tool's use case (currency conversion of an asking price) and even clarifies that the legacy name is retained only for compatibility. However, it does not explicitly name alternative tools for related tasks or provide exclusion criteria, so it stops short of a full 5.

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