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

No annotations are provided, so the description carries the burden of behavioral disclosure. It does reveal that the tool returns 'live computed' data and mentions a USDC payment path via x402, but the wording is ambiguous and the description omits return format, latency behavior, authentication needs, or whether the 'Price 0.05' is a cost or an output field. This is insufficient for a tool with no annotation safety net.

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 short and has no filler, and it front-loads the primary action after the label. However, it is structured as one dense, multi-colon sentence that packs together signal math, rankings, and a cryptic x402 payment reference without clear separation. It is concise but not optimally structured for quick parsing.

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?

The tool has no output schema and no annotations, yet the description does not explain what the response contains, how the composite signal should be interpreted, what the four underlying series are, or how the x402/USDC mechanics work. For a paid/composite finance-signal tool, these are material gaps that an agent needs to call and use it 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 description coverage is 100%, so the wallet parameter is already documented in the schema with concrete detail about free-tier credits. The main description adds no parameter semantics of its own, but that is acceptable because the schema carries the full burden. 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?

The description identifies an action ('get live computed signal') and a resource ('Composite processed layer across 4 series'), so it is not a tautology. However, it never names the four series, does not clearly tie the tool to FX beyond the tool name, and uses 'plus a plain Price 0.05 via x402 (USDC on Base)' ambiguously. This is a vague purpose that does not clearly distinguish among the many processed_* siblings.

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 guidance about when to choose this tool instead of sibling tools such as processed_fx_rates, processed_no_fx_latest, or other processed_* peers. The description implies it is a live composite signal bundle, but it does not state a use case, prerequisites, or exclusions. An agent cannot infer selection criteria from this text.

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