List Kits

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, but the description adds substantial behavioral context: no arguments, exact return object shape with fields, error behavior ('never raises a protocol error — it returns {"error": ...}'), and retry safety. These details go well beyond the structured annotations.

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?

Every sentence carries necessary information: purpose, free access, no-argument requirement, return format, routing guidance, error contract, and idempotence. The most important usage guidance is front-loaded after the first sentence. No filler or redundancy.

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 zero-parameter read-only tool with an output schema, the description is fully complete. It covers purpose, return structure, usage boundaries versus siblings, error handling, and retry behavior. Nothing an agent needs to call this tool correctly 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?

The tool has zero parameters, so the baseline is 4. The description reinforces this with 'Takes no arguments,' which eliminates any guesswork. Since there are no parameters to explain, the description adds all the clarity needed.

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 opens with a specific verb and resource: 'List the 12 themed kits with pricing and member products.' It clearly differentiates from siblings by noting that get_full_kit is for a kit's full contents and search_catalog is for individual products.

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?

Explicit guidance is provided: 'Use when the caller asks about bundles or bundle pricing.' It also gives direct exclusions: 'Not for individual products (search_catalog) and not for a kit's full contents (get_full_kit).' This leaves no ambiguity about when to select this tool over alternatives.

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