compare_regions

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

With no annotations, the description carries the full burden. "Price" implies a read-only computation, and "Friendly names accepted" hints at tolerant input, but there is no mention of return format, whether results are persisted, auth needs, or error behavior.

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 short, front-loaded sentences with no waste. The second sentence is a terse fragment, but it adds a genuinely useful input nuance.

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 3-parameter tool with zero annotations and no output schema, the description is thin: it omits what the comparison result looks like, how billing applies across regions, and whether the call has side effects.

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 0% across 3 parameters. Only the regions parameter gets any elucidation (friendly names rather than codes); the items object shape and the billing enum (ondemand/monthly/yearly) are not explained in the description, leaving most semantics to be inferred.

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 ("Price") and resource ("bill of materials in several regions"), making clear it's a multi-region pricing comparison. It implicitly separates itself from compare_modes and list_regions, but never names them, so sibling differentiation is only partial.

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 implies the use case (compare prices across regions) but gives no conditions for choosing this over compare_modes, quote, or list_regions, and no exclusions or prerequisites.

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