delivery_time

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

With no annotations, the description must carry the full burden of behavioral disclosure. It only states the calculation of delivery times without mentioning whether it is an estimate, what data it relies on, whether it is read-only, or any side effects. This is minimal and leaves significant unknown behavior for a tool with no annotation support.

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 a single, focused sentence that gets straight to the point. It is concise and front-loads the core function, with no redundant text. It could be slightly more detailed without losing conciseness, but it is appropriately sized for a simple tool.

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?

Given the tool has four parameters including enums, no output schema, and no annotations, the description is insufficiently complete. It does not clarify what the tool returns (e.g., estimated days, date range), how mail_type and mail_category affect the calculation, or any limitations. An agent would be left uncertain about the tool's expected output and applicability.

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 100%, so the schema already documents all parameters including formats and defaults. The description adds no extra meaning about parameters beyond implying the two indices from the phrase 'between two indices,' which the schema already covers. Thus it meets the baseline without enhancing understanding.

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 clearly states the action (расчёт) and the resource (сроки доставки) with a specific scope (between two indices). It differentiates from siblings like track (tracking parcels) and zip_lookup (postal code info) by focusing on delivery time calculation, so an agent can identify its purpose without ambiguity.

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 provides no guidance on when to use this tool versus alternatives. It does not mention scenarios, exclusions, or refer to sibling tools. An agent receives no contextual hints about when delivery_time is the appropriate choice, leaving usage entirely implicit.

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