Compare Prices

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

No annotations, so the description carries the burden. It discloses one useful behavioral fact — a query also fans out to the retailer APIs, implying extra cost/latency — but says nothing about SerpApi quota, auth, or what happens when neither optional parameter is supplied.

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?

Front-loaded and only two sentences plus a compact output fragment, with no filler. The trailing 'data: [{merchant, price, url}] ascending' fragment is slightly telegraphic but informative.

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?

Adequate for a simple two-optional-parameter read tool with an output schema (so return values needn't be spelled out). Gaps remain around the both/neither parameter case and external API prerequisites, which matter since no annotations exist.

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 0%, so the description must compensate, and it does: product_id is identified as the SerpApi id from search_products, and query is described as also hitting retailer APIs. It omits whether the two are mutually exclusive or what occurs if both/neither are passed.

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-like outcome ('Per-merchant offers for one product') with clear scope, which distinguishes it from search_products and get_price_history. It stops short of explicitly naming which sibling to use instead, but the resource and granularity are unambiguous.

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?

Gives clear context: pass the product_id returned by search_products, or fall back to a query. This implies the search_products -> compare_prices workflow. No explicit when-not guidance (e.g. vs. get_deals or get_price_history) is given.

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