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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=true, so the safety profile is covered. The description adds that it provides a score, trend, and comparison with historical prices, which is useful output context but not deep behavioral detail (e.g., data sources, performance). This is consistent with annotations, so no contradiction.

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, focused sentence that directly conveys the tool's purpose and core outputs. Every word earns its place; there is no fluff or redundancy.

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 simple one-parameter, read-only tool with rich annotations, the description provides adequate context by listing the key output components (score, trend, comparison). However, with no output schema, a bit more detail on the exact return format or data granularity could enhance completeness, but it is not critical given the low complexity.

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 input schema provides 100% coverage with productId described as 'Product UUID to analyze.' The tool description does not add additional parameter semantics beyond the schema. Since the schema already explains the parameter, 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's function: analyzing whether the current price is a good deal. It mentions specific outputs (score, trend, comparison with historical prices) and uses a distinct verb ('Analyze') with a specific resource (current price). This distinguishes it from siblings like cf_price_history or cf_price_summary, which focus on raw data rather than judgment.

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 implies when to use the tool (when a deal analysis is needed) but does not explicitly mention alternatives or exclusions. Unlike the calibration example where an alternative tool was named, there is no guidance like 'use cf_price_history for raw historical data.' The context is clear but lacks explicit disambiguation.

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