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

With no annotations, the description carries the burden of behavioral disclosure. It mentions unbroken snapshots since a specific date, which is useful context. However, it does not disclose data volume limits, pagination, or the structure of the returned series. The description adds some behavioral context but is not comprehensive for a data retrieval tool.

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 concise (one sentence) and front-loads the core purpose. However, it also includes an implied usage hint and a data quality note, which are relevant but not structured. Overall, it is efficient with no filler words.

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 retrieval tool with 2 parameters and no output schema, the description is moderately complete: it explains the data scope and the interpretative value. But it lacks any mention of the response format, data volume, or how to handle edge cases, which could be necessary for the agent to handle results correctly. With no output schema, more detail on return value could be expected.

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 coverage is 100%, so both parameters (days, product_id) are already described in the schema. The description does not add new meaning beyond what the schema provides; it reinforces the product_id and the historical nature but adds no additional syntax or format details. 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 retrieves daily price snapshots per retailer, which is a specific verb+resource. It does not explicitly differentiate from siblings like get_current_prices, but it adds context about the data source and temporal coverage. The core purpose is clear, but sibling differentiation is only implicit.

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 guidance on when to use this tool versus alternatives like get_current_prices or compare_prices. The description implies it is for historical analysis ('whether a discount is genuine'), but does not state when not to use it or mention alternatives. The agent is left to infer usage from the context.

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