list_regions

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

With no annotations provided, the description carries full burden for behavioral disclosure. The verb 'List' implies a read operation, but the description doesn't explicitly state the operation is safe/read-only, nor does it disclose any response format, pagination, or error behavior. It adds minimal information beyond the basic purpose.

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 compact, front-loaded with the purpose, and includes an args section that is directly useful. Every sentence earns its place, with no redundancy or fluff. The structure is ideal for a simple tool.

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 the tool's simplicity and the existence of an output schema, the description is minimally sufficient. It covers the core purpose and parameter semantics, but lacks any extra context such as typical use cases, comparison with siblings, or explicit read-only confirmation. It is adequate but has noticeable gaps for a tool without annotations.

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 schema provides only the parameter name/type (service_name, string/null, default null) with 0% schema description coverage. The description meaningfully explains the parameter's role: 'If provided, only show regions where this service is available.' This compensation is precise and helpful.

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 opens with 'List available Azure regions,' which is a specific verb+resource statement that clearly distinguishes this tool from its siblings (search_prices, estimate_cost, list_services, compare_regions). It also adds a useful qualifier about filtering by service_name, making the behavior explicit.

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 usage for listing Azure regions but provides no explicit guidance on when to use this tool over alternatives like compare_regions or list_services. There is no mention of exclusions or context. The purpose is clear enough to infer, but the tool lacks any direct guidance.

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