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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explains the statuses ('published' vs 'filling-up'), that all kits have null price and for_sale false, that filling-up parts are usable immediately, and that plans are free. This adds significant real-world semantics beyond the schema, though it doesn't describe the response format or pagination.

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 longer than average but every sentence contributes distinct information: definition, usage context, status meanings, pricing caveat, and routing to get_kit. It is structured logically, though slightly dense and could be tightened without losing meaning.

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?

The description covers kit semantics, statuses, pricing, and the sibling get_kit, which is strong context. However, it never explicitly states what the tool returns, such as 'a list of all kits' or whether the list is sorted or filterable. Since there is no output schema and no annotations, this is a meaningful gap.

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 input schema has zero parameters, so there is no parameter semantics to document. The description still adds value by explaining data fields like price_usd and for_sale, which helps the agent interpret results even though they are not input parameters.

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 explains what kits are and when to use them, but it never explicitly states the tool's action—there is no verb like 'list' or 'returns all kits.' It relies on the tool name for the core action and only implies the listing behavior through 'Use get_kit to fetch either.' This is clearer than a tautology but still vague about the tool's actual operation.

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?

It gives explicit guidance: 'Reach for a kit when the user is building a whole environment rather than looking for one object,' which directly addresses when to use this tool. It also names get_kit as the alternative for fetching a specific kit, so an agent can distinguish the two.

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