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

With no annotations, the description must disclose side effects, access needs, or expected output. It states the tool tracks and costs $0.01 USDC, but does not say whether the call is read-only, what information it returns, or any limitations such as barcode format requirements.

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 one front-loaded sentence with no filler, and the price is useful supplemental information. Every word earns its place.

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?

This is a low-complexity, one-parameter tool, but with no output schema the description should still indicate what result to expect from tracking. It does not mention return data, errors, or input format, leaving an agent without full invocation context.

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 input schema has no descriptions for the sole 'barcode' parameter. The description adds that the barcode is a Russian Post tracking number, which clarifies meaning, but does not give format, examples, or constraints needed to validate the input.

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 exact operation in Russian: tracking a Russian Post shipment by tracking number. This clearly distinguishes it from sibling postal tools like pochta_address, pochta_tariff, and pochta_offices, which cover different purposes.

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 phrase 'tracking shipment by track number' gives a clear context for when to call this tool: when the user has a Russian Post tracking/barcode and wants shipment status. It does not explicitly rule out adjacent tools like pochta_delivery or pochta_delivery_time, so it falls short of a 5.

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