dx

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

No annotations are provided, so the description carries full burden for behavioral disclosure. The description only states what the tool does at a high level ('Fetch directional movement index') without explaining what 'fetch' entails - whether it's a read operation, if it requires authentication, rate limits, data freshness, error behavior, or what format the results come in. For a financial data tool with 5 parameters, this is critically insufficient.

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 maximally concise - a single 4-word phrase that gets straight to the point. There's zero wasted language or unnecessary elaboration. While this conciseness comes at the cost of completeness, as a standalone assessment of conciseness and structure, it's perfect.

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?

Given the complexity (financial indicator calculation with 5 parameters), zero annotation coverage, zero schema description coverage, and no output schema, the description is completely inadequate. It doesn't explain what a directional movement index is, how parameters affect it, what data is returned, or any behavioral characteristics. The description fails to provide the minimal context needed for effective tool 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 0%, meaning none of the 5 parameters (symbol, interval, month, time_period, datatype) have descriptions in the schema. The tool description provides absolutely no information about any parameters - not what they mean, what values they accept, or how they affect the directional movement index calculation. This leaves all parameters completely undocumented.

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 'Fetch directional movement index' states a verb ('Fetch') and resource ('directional movement index'), but it's vague about what this actually does - it doesn't explain what a directional movement index is or what specific data is retrieved. It doesn't distinguish from siblings like 'adx' or 'adxr' which appear related. The description is better than a tautology but lacks specificity.

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 provides no guidance on when to use this tool versus alternatives. With numerous sibling tools including 'adx' and 'adxr' that appear to be related technical indicators, there's no indication of when this specific directional movement index tool should be selected over those alternatives. No context, prerequisites, or exclusions are mentioned.

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