Forecast (naive, with prediction intervals)

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

Annotations cover the safety profile (readOnlyHint, openWorldHint), lowering the bar, and the description adds substantial method transparency: OLS prediction intervals at 80%/95%, automatic detection and reporting of structural breaks, and the since_break fitting behavior. It does not mention data source, computational cost, or fallback when history is insufficient, keeping it from a 5.

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?

Three tight sentences with the core purpose front-loaded, followed by statistical detail and the caveat. Every sentence carries weight, though the density of clauses makes it slightly heavier than necessary.

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 7-parameter, read-only forecasting tool with an output schema already covering return structure, the description supplies the semantic framing an agent needs: method, interval semantics, break handling, and an explicit caveat. Nothing critical is missing, though failure/edge-case behavior is not mentioned.

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?

With 100% schema description coverage the schema already documents every parameter, so baseline is 3. The description's references to since_break, chart types and the horizon largely restate what the schema already says, adding little new syntax or format meaning.

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?

States a specific verb+resource with method and scope: 'Naive linear projection of a displacement metric 1–5 years ahead, based on the last 10 years.' This clearly separates it from siblings like trend_analysis (historical description) and latest_statistics. It does not name any sibling explicitly, so it falls just short of a 5.

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?

It gives genuine usage context for one parameter ('since_break=true fits only the data after the latest break') and a presentation rule ('always present it with that caveat'). However it never states when to reach for this tool versus trend_analysis or other forecasting-adjacent siblings, so the guidance is implied rather than explicit.

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