get_regions

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

Annotations include readOnlyHint: true, so the agent knows this is a read operation. The description adds the return format: 'Object with list of regions (start, end, name, index).' This is useful, but it doesn't disclose any other behavioral traits, such as whether the list is sorted, whether regions include markers, or if there are any limits. Since the annotation covers safety, the description adds minimal extra context, so a 2 is appropriate – it provides the return structure but nothing more.

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 sentences: the first states the purpose, the second lists the return fields. It is concise and front-loaded with the main action. However, the return format could be integrated into a single sentence, but it's not overly verbose. A 4 is fair – efficient but not perfectly streamlined.

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 zero parameters, no output schema, and a simple read operation, the description is fairly complete. It tells the agent what it returns. However, it doesn't specify the exact structure (e.g., array vs. object), or whether the list is sorted, or if it includes empty regions. But for a simple getter, the agent can likely infer the usage. A 3 is a reasonable baseline – adequate but with minor gaps in return format detail.

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 has zero parameters, and the schema coverage is 100% (trivially, since there are no properties). With no parameters, the baseline is 4. The description doesn't need to explain parameters because there are none. This is a perfect score for a parameterless tool.

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 clear purpose: 'Get all regions in the project.' It specifies the resource (regions) and the scope (all in the project). It does not explicitly distinguish from sibling tools like add_region, delete_region, go_to_region, but the list of sibling tools includes those, and the 'Get all' phrasing makes it clear it's a retrieval, not a mutation. A 4 is appropriate because it's clear but lacks explicit sibling differentiation.

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 (when you need a list of all regions), but it doesn't explicitly state when not to use it or mention alternatives. For example, it doesn't say 'use get_markers for markers' or 'use go_to_region to navigate.' Given the tool is a straightforward getter, the context is fairly obvious, so a 3 is fair – it's clear but no exclusions or alternatives are named.

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