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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds genuinely new context: the ~90-day tracking window and the exact shape of what is reported (current low, period low/high, drop since tracking began, weekly lows). With no output schema, this disclosure is doing real work; it stops short of notes on data freshness, missing products, or coverage limits.

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, front-loaded with scope and followed by input forms; every clause carries information and there is no filler. The first sentence is dense but still readable.

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 read tool with safety annotations, the description covers both the query scope and the returned fields, which compensates for the absent output schema. It lacks only edge-case behavior (unknown ids, no history yet, non-Lebanese products), which is minor here.

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?

Only one parameter with 100% schema description coverage, so the schema already carries the accepted input forms. The description restates the same id//product///laptop/ URL formats, adding no syntax, normalization, or error-handling detail beyond the schema.

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 resource and scope: the lowest price of ONE product across Lebanese shops over ~90 days, plus the exact aggregates returned. This separates it from search_products and cheapest_in_category by implication, but it never names a sibling or explicitly rules them out.

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?

Usage is implied by scope ('one product', 'last ~90 days', historical aggregates) rather than stated. There is no explicit when-to-use, when-not-to-use, or pointer to get_product_prices for current prices, leaving routing to the agent's inference.

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