compare_courier_rates

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

No annotations are provided, so the description must carry the full behavioral burden. It states that the comparison is real-time and that it recommends based on cost vs speed, but it does not disclose whether this is a read-only operation, whether external APIs are called, or any side effects or latency characteristics.

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 sentences deliver the core function and the recommendation value without filler. The main verb appears first and each clause adds useful information, making the description easy to scan and act on.

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?

With no output schema and no annotations, the description covers inputs and high-level behavior but does not explain how results are returned or how the priority parameter affects output. This leaves a moderate gap for an agent that needs to parse the recommendation result.

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 baseline is 3. The description maps recipient_address, weight_kg, and cod_amount to the real-world inputs, and 'cost vs speed' loosely reflects the priority parameter, but it adds no additional syntax or precedence details beyond what the schema already provides.

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 uses a specific verb ('compare') with a concrete resource: real-time tariff and SLA comparison across four named couriers. It also states a clear outcome (recommends the optimal carrier), which distinguishes it from siblings like list_couriers and create_parcel.

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 clearly establishes the intended scenario: comparing courier rates and SLAs for a destination, parcel weight, and COD amount. However, it does not explicitly state when not to use the tool or mention alternatives such as calculate_delivery_zone_and_fee.

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