list_regions

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

Annotations already declare readOnlyHint=true and idempotentHint=true, indicating safe read operation. The description adds valuable context about output format differences based on filter or limit parameter, which goes beyond the annotations.

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 two concise sentences. First sentence states the core purpose, second explains output behavior under different conditions. No unnecessary words.

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?

Given 11 parameters and no output schema, the description explains the two modes (filtered/unfiltered) but lacks detail on what the compact summary contains or what full region objects include. It also does not guide the user to sibling tools for specific filters.

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?

All 11 parameters are documented in the schema with descriptions (100% coverage). The description adds general behavior about compact vs full output but does not add specific meaning to individual parameters beyond what the schema 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 clearly states the tool lists all cloud regions across all providers, with a specific verb and resource. It also mentions filtering capabilities, which distinguishes it from more specialized sibling tools like find_gpu_regions or find_compliant_regions.

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 provides clear guidance on when to use no filter (compact summary) vs with filter (full objects). It does not explicitly mention alternatives or when not to use this tool, but the context signals show many siblings, so the differentiation is implicit.

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