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

With no annotations, the description carries the full burden of behavioral disclosure. It implies a read operation (historical data retrieval) but does not explicitly state read-only behavior, rate limits, data freshness, or any side effects. The mention of 'daily closes + range change' only hints at output shape without full transparency.

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 fragmented phrase rather than a well-structured sentence. While short, it sacrifices clarity and completeness. Under-specification rather than conciseness.

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 no output schema, the description should fully explain the return value. 'Daily closes + range change' is vague—does it return one object per day? What is the range change formula? The tool is simple (2 params), but the description omits essential details about the output structure, making it incomplete.

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%, and the description adds no explanation of the parameters. The phrase 'for a symbol' loosely suggests the 'symbol' parameter, but the 'days' parameter and the meaning of 'range change' are not elaborated. The description fails to compensate for the lack of schema descriptions.

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 'Daily closes + range change for a symbol' clearly indicates the tool returns daily closing prices and a range change metric for a given symbol. It is specific about the data resource, though it lacks an explicit verb. It distinguishes from sibling tools like 'candles' (OHLC) and 'calendar', but does not explicitly differentiate.

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?

No usage guidance is provided. The description does not specify when to use this tool over alternatives like 'candles' for detailed OHLC data or 'context' for broader market data. There is no mention of prerequisites, filters, or context in which this tool is appropriate.

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