search_product_urls

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

With no annotations, the description carries the full burden of disclosing behavior. It clearly states 'Discovery only,' explains that it does not download or scrape images, and notes that it returns 'ranked' URLs — this goes beyond the mere title and gives the agent expectations about side effects and output ordering. It doesn't cover rate limits or auth, but these are less critical for a discovery-only read operation.

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 well-structured with clear headings and short bullet sections. It front-loads the core purpose in one sentence, and every section (why, examples, returns) earns its place without redundant wording or filler.

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 three-parameter discovery tool with complete schema documentation and an output schema, the description is sufficient for an agent to select and invoke it correctly. It gives purpose, usage context, concrete examples, and a clear statement of the return type, so no critical information is missing.

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 description coverage is 100%, so the schema already documents each parameter's meaning and example values. The description adds example calls showing how query, max_urls, and site_filter are combined, but this does not materially extend the parameter semantics beyond what the schema provides. 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 first sentence states a specific action and target: 'Discovers and ranks candidate e-commerce product pages for a given query (Discovery only).' It clearly identifies this as a discovery/preview tool rather than a scraping tool, and distinguishes it from siblings like fetch_product_images and scrape_single_url by explicitly noting it does not download or scrape images.

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?

The 'USE THIS TOOL WHEN' section provides clear use cases: finding authoritative PDPs and previewing URLs before scraping. This effectively implies when not to use it (when you need images or actual page content), though it never names sibling alternatives directly or states explicit exclusions. The example calls further clarify how to invoke it.

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