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

Even without annotations, the description discloses key behavioral traits: it is a read-only operation ('View'), it includes trend analysis, and it depends on prior data from track_price. This goes beyond the tool name and schema, providing useful context about the tool's dependency and output nature.

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 three sentences, front-loaded with the primary purpose, and includes the necessary dependency note. Every sentence adds value without 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?

The tool is simple with no output schema, but the description covers the core functionality, trend analysis, and the prerequisite. It could mention what happens if no history exists or how asin/query are used in combination, but overall it provides a solid understanding for a straightforward tool.

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 has 100% description coverage for all three parameters (asin, limit, query), each with clear descriptions. The tool description does not add additional parameter semantics beyond the schema, so the baseline of 3 applies.

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: 'View stored price history for a product with trend analysis (rising/falling/stable)'. It specifies the resource (price history) and the action (view), and distinguishes itself from siblings like track_price by referencing it as a prerequisite. The mention of min, max, and average prices further clarifies scope.

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 provides clear context: it should be used after track_price has been called to build up history data. This implies the tool is for historical analysis, not for real-time tracking. It does not explicitly exclude other alternatives (e.g., compare_prices), but the prerequisite gives a clear usage condition, qualifying as 'clear context, no exclusions'.

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