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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds genuinely useful behavior: the exact shape of returned fields, that location is city-level, and a cost signal ("1 credit") that no structured field carries. It does not mention pagination semantics for the page parameter, which keeps it from a 5.

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?

Four short clauses with no filler: purpose, returns, sibling hand-off, location, cost. Everything is front-loaded and each clause carries distinct information.

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?

With no output schema, the description usefully enumerates the return fields, and the cost and follow-up routing complete the picture for a search tool. The remaining gap is pagination/page behavior and query string expectations, which an agent would have to infer.

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 50%; uule, country, and location are already well documented in the schema. The description only re-states location as "optional city-level", and adds nothing about page, query limits, or language. It neither compensates for the gap nor misleads, so baseline 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?

States a specific verb and resource ("Search Google Shopping") and enumerates the return fields (title, price, merchant, rating, product_id). It also distinguishes itself from the sibling tools by saying the returned product_id feeds google_shopping_sellers or google_shopping_product.

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?

Explicitly tells the agent to use product_id with google_shopping_sellers/google_shopping_product as a follow-up step, and notes location is an optional city-level refinement. It lacks an explicit "when not to use" statement (e.g., for a single known product, call google_shopping_product instead), so it stops short of full routing guidance.

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