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

With no annotations, the description carries the burden of explaining behavior. It discloses the data returned, the stored/non-verified nature of the prices, and the limitation that these are not exact-variant buyable offers. It could add more about freshness or response shape, but it is substantially transparent for a simple getter.

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?

Two sentences with no filler. The core action and contained data are front-loaded, and the caveat plus alternative routing are placed in the second sentence. Every clause earns its place.

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 single-parameter tool with no output schema, the description explains what the result contains, what it excludes, and when to choose an alternative. It stops short of describing the exact return shape or potential failure modes, but an agent has enough context to invoke it correctly.

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 the schema already documents product_id as the canonical product uuid from search_products. The description adds little beyond the phrase 'one canonical product', which is already implied by the parameter description. 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 uses specific language: it retrieves the latest stored advertised prices, stock observations, and affiliate links for one canonical product. It also explicitly distinguishes itself from verified-offer tools, so an agent can tell it apart from siblings without reading schemas.

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 a clear when-to-use rule: use this when you need stored advertised prices for a canonical product, and switch to get_verified_offer when a marketplace source ID is known. The explicit 'not exact-variant verified buyable offers' caveat also prevents misuse.

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