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

With no annotations, the description carries the behavioral burden. It helpfully discloses conditional availability ('if the restaurant has one'), signalling the result may be absent, but it does not say whether the absence yields an empty result or an error, nor anything about return shape.

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?

Short and front-loaded on the resource. The bilingual Russian/English duplication roughly doubles the length for the same content, which is mild redundancy rather than bloat.

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 zero-parameter, read-only lookup with no output schema, the description does useful work by naming the payload (link, conditions, phone) and flagging that it exists only if the restaurant offers delivery. Only the empty/absent-result behavior is left unstated.

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?

The schema has zero parameters, so there is nothing for the description to disambiguate. Baseline of 4 applies for a no-argument tool whose inputs are fully determined by context.

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 resource: delivery/takeaway ordering link, plus the conditions and phone number that accompany it. It is clearly separable from siblings like get_reservation_link or get_restaurant_info by topic, though no explicit verb frames the retrieval.

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 only implied by the resource name – an agent infers 'call this when the user wants delivery or takeaway'. There is no explicit when-to-use, no exclusion, and no named alternative (e.g., get_reservation_link for dine-in booking).

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