compare_courier_rates

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

With no annotations, the description must carry the behavior burden. It discloses that quotes are 'live' (implying external carrier calls and possible latency) and that it selects an optimal provider, but never states whether this is a pure read/quote operation or has side effects, nor any rate limits or failure modes.

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, front-loaded with the core purpose and then the inputs/differentiators. Slight redundancy between 'Multi-carrier pricing and SLA comparison engine' and 'compares live rate quotes side-by-side across...', but no padding of consequence.

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 annotations and no output schema, the description should at least sketch what comes back (e.g., a ranked list of quotes with price and SLA) and whether invoking it commits to anything. It omits the return shape entirely, leaving a meaningful gap for a comparison tool.

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 all four parameters (including the priority enum and defaults) are already documented in the schema. The description only restates weight, COD, and priority at a high level, adding no format, unit, or edge-case detail beyond the schema — baseline 3 applies.

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 verb and resource ('compares live rate quotes side-by-side') and enumerates the exact carriers (Steadfast, Pathao, RedX, Paperfly), plus the optimization axes. This clearly distinguishes it from siblings like list_couriers (enumeration) and calculate_delivery_zone_and_fee (single-zone fee).

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?

Gives clear context: use it when choosing an optimal provider based on weight, COD value, and priority. It does not say when NOT to use it or explicitly point to alternatives such as calculate_delivery_zone_and_fee or list_couriers, so it stops short of full routing guidance.

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