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

With no annotations provided, the description carries the full burden of disclosing behavior. It only mentions the use of the FMP EMA API and historical price data, but does not describe output format, data range behavior, authentication needs, or whether the result is a single value or time series. This is a significant gap for a tool with no structured behavior context.

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 concise, consisting of two sentences. The first sentence states the function, and the second adds a brief use case. There is no redundancy or filler, and it is appropriately front-loaded.

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, so the description should explain what the tool returns. It only says 'calculate the EMA' without indicating whether the output is a single value, a series, or how it is structured. This leaves the agent uncertain about the result, especially given the optional from/to date parameters that suggest a time series.

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 schema description coverage is 100%, so the input schema already documents all five parameters (symbol, periodLength, timeframe, from, to) with descriptions. The tool description adds no additional parameter-specific meaning, so it does not enhance what the schema provides, but also does not need to compensate.

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 states the tool calculates the Exponential Moving Average (EMA) for a stock, using a specific verb ('Calculate') and resource ('EMA for a stock'). This distinguishes it from sibling tools like getSMA, getDEMA, and getTEMA, making the purpose unambiguous.

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 implied usage context by mentioning trend analysis and buy/sell signals, but it does not explicitly state when to prefer this tool over alternatives like getSMA or getRSI. No exclusions or alternative tool names are mentioned, leaving usage guidance somewhat implicit.

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