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

No annotations are provided, so the description carries the burden. It identifies the data source (FMP ADX API) and the use of historical price data, which is useful. However, it does not disclose output format, limitations, or error conditions, though the read-only nature of a calculation is fairly clear.

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 two concise sentences with no fluff. The first sentence states the core action and resource; the second adds context about the tool's purpose without redundancy.

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 simple indicator tool with no output schema and no annotations, the description gives enough context for selection—it names the indicator, its purpose, and data source. Invocation details are fully covered by the schema. A mention of the return structure would be nice, but the description is adequate for the tool's simplicity.

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 input schema has 100% coverage with descriptions for all parameters. The description adds no extra meaning to the parameters beyond what the schema already provides, such as periodLength being 'for the indicator'—so the baseline score 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 clearly identifies the action ('Calculate ADX') and the resource ('a stock'), and explains what ADX measures (trend strength and direction). It is specific to this tool, but it does not explicitly differentiate from sibling indicator tools like getRSI or getSMA.

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 a use case (analyzing trend strength and direction) but does not explicitly state when to choose this tool over alternatives such as getRSI or getEMA. There is no mention of exclusions or preferred scenarios beyond the general purpose.

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