list_carriers

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

With no annotations, the description carries the full behavioral burden. It discloses the return envelope ('status', 'count', 'carriers') and field meanings, which is useful, but says nothing about auth requirements, rate limits, caching/freshness, or whether the carrier set is static — mild gaps for a read-only listing.

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?

Purpose and usage are front-loaded in the first sentence, and the return block is compact. The 'Returns:' section partially duplicates the existing output schema, keeping it just short of maximally efficient.

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 simple, parameterless listing tool with an output schema already present, the description covers what the tool is, what it returns, and why an agent would call it. Nothing needed to invoke it correctly is missing.

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 tool takes no parameters, so there is nothing to disambiguate; the baseline for a 0-param tool is 4. The description instead spends its detail budget on the returned fields, which is the right trade-off.

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 ('List carrier partners') and enumerates the exposed fields (modes, INR rate card, reliability, average speed). No sibling tool deals with carriers, so the scope is unambiguous against list_shipments, list_warehouses, list_vehicles, etc.

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?

'use for quoting and choosing a carrier' gives a concrete use context, which is more than most list tools offer. It stops short of naming alternatives or stating when not to use it, but for a zero-param read tool the guidance is adequate.

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