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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered elsewhere. The description's only added behavioral context is provenance (IMF World Economic Outlook); it says nothing about availability by country/year, units of the returned factor, or what happens when a year is missing.

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?

A single front-loaded sentence with zero filler, though it is a noun phrase without a verb, which slightly softens the action statement. Nothing is redundant, but equally nothing is layered for scanning.

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 returned number represents (base currency, index vs. ratio, scale), and that is absent. Annotations and the fully documented schema cover the input side, making the definition minimally viable but not 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?

Schema description coverage is 100%, with both country (ISO alpha-3) and year (defaulting to the configured current PPP year, 2024) fully documented in the schema. The description's 'a single country' and 'for a year' merely restate the parameters without adding format, constraint, or edge-case detail, so the baseline of 3 applies.

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?

Names a specific resource (a single country's PPP conversion factor), scopes it by country and year, and cites the data source (IMF WEO). It is clear what the tool returns, but it never contrasts itself with the sibling analyze_ppp, so an agent cannot tell from the description alone which of the two to pick.

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?

There is no explicit when-to-use or when-not-to-use guidance; the only signal is the implicit 'fetch one value' framing. With siblings named analyze_ppp, get_history, and convert, the definition offers no routing help at all.

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