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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds the API endpoint and the field groups returned, but says nothing about error behavior for unknown codes or pagination, which is acceptable given annotation coverage.

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 compact clauses: what it returns, then the endpoint. Front-loaded with the identifying resource and code example, zero filler.

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?

With no output schema, the description usefully enumerates the returned field groups (prices, VAT, variants, custom fields), which is the main thing an agent needs. A note on behavior for a missing/invalid code would round it out, but nothing essential 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?

Schema description coverage is 100%, so both parameters are already documented in the schema. The description contributes the concrete code example (SP.00192), giving useful format intuition, but otherwise defers to the schema — the baseline 3 applies.

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 ('One product by its code') and enumerates what the response contains (prices, unit, category, VAT, variants, custom fields), which distinguishes it from getfly_list_products without naming it explicitly. The sibling differentiation is implied by 'one product' rather than stated.

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?

Usage is implied — fetch a single product when you have its code — but there is no explicit when-to-use/when-not guidance and no mention of getfly_list_products as the alternative for searching by name or listing.

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