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

With no annotations, the description carries the behavioral burden. It adds one genuine behavioral trait ('not a trigger') and frames the tool as a context read, but it omits data source, refresh cadence, or interpretation details. No contradiction with annotations.

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 appropriately short and front-loads the asset list before the usage caveat. However, 'UW' is unexplained shorthand, pushing it slightly from concise toward under-specified.

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 empty parameter list and presence of an output schema lower the burden, and the not-a-trigger caveat is essential. Still, the cryptic 'UW' and lack of any relationship to related risk tools leaves an agent without full confidence in sibling selection.

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 tool has zero parameters and schema coverage is 100%, so there is no parameter meaning for the description to add. The baseline of 4 applies because no parameter documentation gap exists.

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 names concrete assets (VIX, TNX, UUP) and assigns a purpose ('risk-tone overlay'), so an agent can roughly tell what it does. However, it lacks a clear verb—'UW' is cryptic—and it does not sharply distinguish this from overlapping risk/sentiment siblings such as get_fear_greed or get_index_health.

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 'risk-tone overlay — not a trigger' phrase gives an implied usage context and an explicit exclusion, which is more than no guidance. But it never names alternative tools or states when an agent should prefer this over other risk-related getters.

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