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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds only that this is a check performed without opening the booking card, which reinforces non-mutation but says nothing about rate limits, data freshness, or how availability is determined across venues.

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 short sentences: the first declares the output, the second declares the trigger. Nothing is redundant and the core purpose is front-loaded.

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 two-parameter read-only availability lookup with full annotation coverage, the description covers purpose and invocation trigger adequately. The main residual gap is the shape of the returned slots, which matters since there is no output schema.

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 only 50%: date documents its YYYY-MM-DD format, but venue_id has no description at all. The description refers only vaguely to "конкретну дату" and "столика" and never clarifies whether venue_id is an internal ID, slug, or name, so it does not compensate for the schema gap.

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 states a specific verb and resource: it returns free table-booking slots for a given date ("Повертає вільні слоти для бронювання столика на конкретну дату"). That clearly separates it from reservation-making siblings like restaurant_reservation or confirm_reservation, though it never names those siblings explicitly.

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 gives a concrete trigger: call it when the user asks "is there space at 19:00" without opening the booking card, which implicitly frames it as a lightweight pre-check rather than a booking action. There is no explicit when-not-to-use statement or named alternative tool, so it falls short of the top band.

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