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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is fully covered. The description adds essentially no behavioral context beyond that – nothing about rate sourcing, how stale rates default on the `date` field, or what a PPP adjustment does to the numeric result.

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 compact sentence with no wasted wording, front-loaded on the core action. It is efficient, though its brevity edges toward under-specification rather than optimal density.

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?

For a 5-parameter tool with no output schema, the definition leaves the agent to infer the return shape (converted amount vs. rate) and multi-target behavior from the schema's comma-separated `to` field. The rich schema descriptions compensate substantially, making this adequate 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%, so every parameter (from, to, amount, date, ppp) is already fully documented with formats and the CUR:COUNTRY syntax. The description only restates the amount-conversion and optional-PPP framing, adding no meaning beyond the schema; baseline 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?

States a specific verb ('Convert') and resource ('an amount between currencies'), which is clearly distinct from rate-listing siblings like get_rates or get_rates_by_base. It does not, however, name or contrast any sibling explicitly, so the differentiation is inferred rather than stated.

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 only usage signal is the 'optionally PPP-adjusted' modifier, which is already visible in the schema's ppp parameter. There is no guidance on when to choose this over get_rates, get_ppp_factor, or analyze_ppp, and no stated prerequisites or exclusions.

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