indicator_nvi

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

With no annotations, the description carries the burden of disclosing behavior. It states that the tool calculates NVI based on price changes on decreasing-volume days, which implies a read-only calculation. However, it does not mention that the tool fetches OHLCV data for the given symbol and timeframe, nor does it describe the output format, which could be important for agent expectations.

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 a single, focused sentence that immediately communicates the tool's purpose. It contains no redundant words, is front-loaded with the primary action, and is appropriately sized for the tool's simplicity.

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 is relatively simple with just three parameters, all fully described in the schema. The description explains the NVI concept, but there is no output schema and no mention of what the tool returns (e.g., an array of NVI values). For a calculation tool, this missing output information is a gap, but the overall description is adequate for basic use.

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 parameters (symbol, limit, timeframe) are already well documented. The description does not add any additional meaning to the parameters beyond the schema, such as explaining that 'timeframe' affects the NVI calculation period. Thus, the baseline score of 3 is appropriate.

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 identifies the tool as calculating the Negative Volume Index (NVI) and explains its behavior ('tracks price changes on days with decreasing volume'). This specific verb+resource combination distinguishes it from sibling indicator tools like indicator_obv or indicator_ema.

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 usage when NVI analysis is desired, but provides no explicit guidance on when to choose this over other indicators or any alternatives. While it defines what NVI does, it does not mention trade-offs, prerequisites, or exclusions, leaving the agent to infer usage from the indicator name.

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