ozon_product_variant_select

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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so safety is covered. The description adds real value by disclosing that the variant and final SKU are re-validated on each call and that a url comes back. It does not say what happens when the variant is invalid, stale or out of stock, which is the main behavioral risk for a re-check tool.

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?

Three short sentences with the action front-loaded and no filler. Density is good; the only weakness is that the last sentence about the returned url muddies the input/output distinction rather than clarifying it.

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?

No output schema exists, so the description should be firmer about what comes back; it mentions a url but not whether the new SKU, price or availability are returned. For a two-parameter selection tool with full annotation coverage this is adequate but leaves the url ambiguity and error behavior unresolved.

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 0%, so the description must carry parameter meaning and only partly does: it explains variantId's source (product_variants) but nothing about the url parameter, and worse, it speaks of a "возвращённый url" while the schema's url is a required input, leaving it ambiguous whether the input url is the product page to switch within or an output. The regex-constrained variant id format is left to the schema alone.

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?

States a specific verb and resource: "Переключить на вариант из product_variants по variantId", and adds two concrete outcomes (re-validates the variant and final SKU, returns a url). This is enough to separate it from the sibling listing tool ozon_product_variants, even though that tool is never named.

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?

Gives downstream usage ("Используйте возвращённый url для карточки и отзывов") but never says when to pick this tool over ozon_product_variants or ozon_product, nor what preconditions exist (must a variant list be fetched first?). Usage is implied rather than stated.

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