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

With no annotations provided, the description carries the full burden. It discloses the key filtering nuance: when a day is given, only offers active that day are returned, plus offers with no day binding. It does not explicitly state that this is a read-only lookup (though 'get_' implies it), nor does it describe return format or any auth/rate-limit behavior, which keeps it at an adequate but not rich level.

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 description is short and front-loaded, with the core resource named first and the day-filtering nuance immediately after. The closing English phrase 'Promotions and lunch offers' is somewhat redundant with the opening Russian text but does not materially harm conciseness.

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 one-parameter read tool with fully documented schema and no output schema, the description supplies the essential filtering behavior and resource scope. The main missing piece is explicit routing guidance against sibling tools, but otherwise an agent has enough to call it correctly.

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%, so the baseline is 3, but the description adds meaningful semantics beyond the schema: when a day is supplied, the result includes both offers active on that day and day-agnostic offers. The schema's day description does not mention the day-agnostic inclusion, so the description genuinely supplements the parameter behavior.

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 names the resource clearly: promotions, business lunches, and special offers (Акции, бизнес-ланчи, спецпредложения). It does not state an explicit verb such as 'returns' or 'lists', and it does not differentiate itself from siblings like get_menu or get_kids_menu by name, but the resource is distinct enough for an agent to recognize it as the promotions lookup.

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 implies when the tool is relevant (looking for current promotions), but it never explicitly says when to use this tool versus get_menu, get_kids_menu, or get_banquets_and_events. The day-related sentence describes filtering behavior rather than usage guidance, leaving the agent to infer the appropriate context.

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