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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: the paid nature (0.01 USDC per call), the 28-day bucket sampling, and the lack of history before 2026-09-05. This goes beyond the annotations and helps the agent understand cost and data availability.

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 information-dense, with the paid cost warning front-loaded, followed by the data format and collection history. Every sentence adds value and there is no fluff.

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 description covers the data source, format, sampling, history start, and cost. It doesn't describe the return structure (no output schema), but for a time-series data tool, the description gives enough context for an agent to call it correctly. The only minor gap is not explicitly stating the response format, but the description is otherwise complete.

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 100%, so the schema already documents all four parameters. The description adds context about the eviction-rate bucket values and the sampling period, but it doesn't add much beyond the schema for parameter semantics. Baseline 3 is appropriate.

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 returns Azure spot eviction-rate history, with specific detail on the 28-day buckets, sampling frequency, and SKU/region scope. It distinguishes itself from sibling tools by naming the exact data source (Azure spot eviction rates) and the metric format.

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 explains the data collection cadence and the date range, and the schema provides defaults for from/to. It doesn't explicitly name alternative tools for other cloud providers or spot pricing data, but the context is clear enough for an agent to know when to use this tool for Azure eviction history.

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