list_regions

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

With no annotations provided, the description carries the burden of behavioral disclosure. It clearly indicates this is a read-only list operation, scoped to the organization, and specifies the return content (slug, label, metadata). It does not explicitly mention auth or rate limits, but for a simple zero-parameter list tool the behavior is sufficiently transparent.

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 concise sentences deliver purpose, examples, return contents, and usage guidance with no filler. The most important information (what the tool lists) is front-loaded, and the practical usage note is placed at the end.

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 zero-parameter, read-only list tool without an output schema, the description provides everything needed: what the tool returns, what scope it covers, and how the result should be consumed. There are no obvious gaps that would prevent an agent from calling it correctly.

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 input schema is empty with zero parameters, so there are no parameter semantics to document. The baseline for zero parameters is 4, and the description adds relevant context about how the output relates to other tools without needing to explain parameters.

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 states a specific verb ('List') and resource ('monitoring regions available to the organization'), with concrete examples ('eu-west-1', 'us-east-1'). It makes the tool's purpose unambiguous and naturally distinguishable from the many sibling list_* tools.

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 explicitly tells the agent where the returned slugs should be used: 'Use these slugs in the regions array of create_check or update_check.' This gives clear downstream guidance. It does not mention when not to use the tool, but no realistic alternative exists among the listed siblings, so 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.