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

No annotations are supplied, so the description must carry the behavioral load: it does state what is returned in unusual detail (including PDF documents such as passports and certificates), which implies a read-only lookup. But it is silent on failure behavior for a bad id/URL, permissions, and whether fetching PDFs is costly or slow, so a mutation-free but non-trivial retrieval tool remains partially opaque.

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 return contents are front-loaded and the parameter note comes second, so the agent can decide relevance in one pass. The field enumeration is long but each item (prices, presence, PDFs) is genuinely discriminating; only slight trimming would help.

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 one required parameter and no output schema, the description does the necessary work by describing the returned payload in detail. The remaining gaps — not-found behavior and whether the URL must be exact — are minor for a single-argument lookup tool.

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 is the only source of meaning for id_or_url, and it adds real value by declaring three accepted forms: an id from usilitel_products_search, an артикул (SKU), or a page URL on usilitel-signala.ru. It stops short of giving the expected URL shape or id format.

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 gives a specific verb+resource ('Полная карточка товара') and then enumerates the exact contents of that card (price, availability, characteristics, photos, PDFs, site description text), which distinguishes it from lightweight siblings such as usilitel_products_search. It also names the sibling that produces the id, anchoring its role in the catalog workflow.

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?

It explicitly says to pass an id obtained from usilitel_products_search, or an SKU, or a product page URL, which tells the agent where this tool sits in the sequence. It does not, however, say when to prefer it over usilitel_products_compare or usilitel_page_text, nor does it state any exclusions.

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