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

Annotations already indicate readOnlyHint and openWorldHint. The description adds meaningful behavioral context beyond these: it explains that each asset may use a different source (ftso oracle or coingecko fallback) and that degraded=true only triggers on a whole upstream failure, not on per-asset fallback or missing fx rates. It also clarifies the fx rate calculation. This goes beyond the basic read-only hint and is valuable.

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 compact and front-loaded with the core purpose. It packs essential nuances (source variation, degraded flag semantics, fx rate formula) into three sentences without unnecessary verbosity. Every sentence contributes information an agent needs to interpret results correctly.

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 tool with one optional parameter and no output schema, the description covers the key aspects an agent needs: what prices are returned, that sources may vary per asset, when degraded is set, and how fx rates work. It could be more explicit about the response structure, but given the low complexity, it is largely complete for correct invocation and interpretation.

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 single parameter 'currencies' is well-defined in the schema with enums and a default list, making its semantics clear without description support. The description does not explicitly explain the parameter, but it mentions the major fiats which map to the enum values. Given the parameter is optional and self-explanatory, the description adds little beyond schema, but does not leave gaps.

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 clearly states the tool retrieves latest prices for FLR, SGB, and XRP in USD and major fiats. It names the exact resources and assets, and is distinguishable from sibling tools like get_ftso_providers which focus on providers rather than prices.

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 implies the tool is used when you need current prices for these specific assets, but it does not explicitly state when to use it versus alternatives or provide any exclusions. There is no mention of alternative tools or conditions under which it should not be used, leaving some inference to the agent.

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