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

Despite no annotations, the description thoroughly discloses behavior: no matching or charging at call time, lazy processing only after user opens link, free usage, no auth required. Also describes response format (Markdown with labeled link). Fully transparent.

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?

Concise yet comprehensive. First sentence states purpose, followed by bullet points with key usage notes. No redundant sentences, every line adds value. Well-structured for quick comprehension.

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?

Given no annotations and no output schema, the description covers all essential aspects: input format, output format, behavioral safety (no charges, no auth), and geographic scope. Complete for an AI agent to select and invoke the tool 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% with descriptions for both parameters. The description adds value by giving examples for shopping_list (e.g., '2 bananas\nmilk') and locale (e.g., 'en-CH'), which clarifies usage beyond the schema definitions. Not a 5 because schema already covers basics well.

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 clearly states the action: turning a free-form shopping list into a Pepesto cart link. It specifies input, output, and context (European supermarkets, no auth). Distinguishes itself from potential alternatives by emphasizing the lazy matching and pricing, making purpose 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?

Explicitly says when to use (free-form shopping list), what not to worry about (no API key, no immediate charges), and how to handle the response (surface Markdown link as-is, avoid showing raw URL or rewriting caption). Provides clear context for usage without references to siblings, but self-contained.

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