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

Annotations already cover read-only/idempotent safety, and the description adds useful behavioral context: price source and currency from the current merchant catalog in RUB, plus the edge-case behavior that unavailable products return no details and may suggest similar items. This goes beyond what the annotations alone provide.

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?

Two sentences, front-loaded with the main action and resource, then efficient supporting detail. Every clause adds value, with no repetition of schema or annotation information.

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 simple read tool with full annotations and no output schema, the description covers the main purpose, region scope, price source, and unavailable-product behavior. It could be slightly richer by referencing how to obtain valid region IDs, but nothing critical is missing for an agent to make a correct call.

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 schema has 0% description coverage, so the description must carry parameter meaning. It does map region_id to 'selected Russian delivery region' and product_id to 'one available product', and 'Russian' aligns with country=RU. However, it does not elaborate on UUID semantics or required relationships beyond that minimal mapping.

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 (Read), a clear resource (product and manufacturer information), and a scoping condition (selected Russian delivery region). This distinguishes it from sibling tools like products_search and product_analogs, making the tool's role immediately identifiable.

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 gives clear context for when to use the tool: when you need details for one specific product in a specific Russian delivery region. It does not explicitly name alternatives or state when not to use it, but the purpose is specific enough that an agent can infer the right context.

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