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

With no annotations, the description carries the burden. It discloses 'INFORMATION ONLY', signalling no trade execution, and the pay-per-use cost model. However, it doesn't describe limitations like data source, period, or whether fees/slippage are included, leaving important behavioral traits hidden.

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 compact and front-loaded with the core purpose, then adds cost and parameter hints. The cryptic 'TRADING(info)' prefix and telegraphic style are minor warts, but there is no redundant content.

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 tool with no output schema, the description omits any indication of the return format (e.g., performance metrics, chart data, trade list). It also lacks defaults for 'dias' and data source, so an agent cannot fully predict the outcome.

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's single 'input' parameter has only a generic 'service input' description, so the tool description adds the crucial mapping 'input=symbol, dias=optional'. This gives the agent the actual semantic content, though it doesn't specify types or defaults.

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 uses a specific verb 'backtest' with a clear resource 'SMA-crossover on historical data', and the 'INFORMATION ONLY' tag further distinguishes it from execution-style trading tools like trading-signal. An agent can tell this from siblings without opening the schema.

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 explicit when-to-use or alternatives are provided. The description implies a use case (SMA crossover historical analysis) but doesn't state when to prefer this over trading-signal or market-data, nor any exclusions. 'INFORMATION ONLY' is the only usage hint.

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