ls_list_variants

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, but the description adds valuable context: pagination format (meta.page with currentPage, lastPage, total) and a conditional cross-store behavior requiring productId when LEMONSQUEEZY_ALLOWED_STORE_IDS is set. It also clarifies that API key scoping is the true enforcement boundary, which is non-obvious and useful.

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 front-loaded with the core purpose, followed by pagination details and a cross-store note. Each sentence adds unique information, but the cross-store sentence is slightly convoluted with awkward capitalization ('Even with that set, Pair with...') and could be tightened. Still, no wasted words.

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 list tool with pagination and an optional filter, the description is fairly complete: it covers the result shape (meta.page fields) and a conditional requirement. No output schema exists, so the pagination mention partially compensates. It does not specify which variant fields are returned, but that is common for list endpoints and not critical.

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 all four parameters well-described. The description ties productId to the 'optionally filtered by product' phrase and explains its necessity in cross-store mode, but it does not add new syntax or format details beyond the schema. 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 description clearly states the tool's purpose with a specific verb and resource: "List all variants, optionally filtered by product." This distinguishes it from sibling tools like ls_get_variant (single variant) and ls_list_products (products). The scope (all variants, optional product filter) is 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?

The description implies usage context by mentioning optional product filtering and the cross-store requirement for productId, but it does not explicitly contrast with alternatives or state when not to use it. No exclusions or alternative tool references are provided, though the 'optionally filtered by product' hints at a common use case.

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