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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds that the tool reveals free vs. paid status and pricing, which is useful output-context. It does not contradict annotations (no annotation_contradiction). However, it adds no detail on output format, pagination, or other behavioral traits beyond the product-content listing.

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 core purpose, followed by the pricing distinction in the second sentence. The long listing of product categories is informative, not redundant, and there is zero filler. Efficiently structured for the information conveyed.

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 only 1 optional parameter (fully schema-documented), no output schema, and no nested objects, this is a low-complexity tool. The description adequately covers what the tool does and what it reveals (product catalog with pricing). A short note on return format would be nice, but the description is essentially complete for this complexity level.

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% – the single optional locale parameter is fully documented with its enum (ru/en) and default (ru) in the schema. The description makes no mention of this parameter, but since the schema does the heavy lifting, the baseline score of 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 starts with a specific verb+resource ('Обзор всех продуктов Arcanika' – overview of all products), enumerates the full catalog (Tarot, decks, Fate Matrix, Pythagorean Square, dream interpretation, etc.), and adds the pricing/free-paid distinction. This clearly distinguishes it from siblings like list_decks and list_spreads, which are narrower subsets, and from calculation tools like calculate_matrix.

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 context is implied: the description frames this as the comprehensive overview tool covering all products and pricing, contrasting with more specific siblings (list_decks, list_spreads). However, there is no explicit when-to-use/when-not-to-use guidance or named alternatives, so the agent must infer the tool's role from scope rather than receive direct instruction.

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