Block Region List

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

With no annotations, the description carries the full burden. The word 'List' implies a read operation, but the description does not disclose the crucial behavior of what happens when theme is null (presumably defaults to the active theme), nor anything about the shape or limitations of the listing.

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?

A single tight sentence with no filler, and the core action is front-loaded. It is arguably under-specified rather than bloated, so conciseness itself is fine.

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 simple one-optional-parameter tool with an output schema present (so return values needn't be described), the description is nearly adequate. The remaining gap is the null/omitted-theme behavior, which an agent genuinely needs to call 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?

Schema description coverage is 0% and the single parameter has a default of null, so the description should clarify the parameter. 'for a theme' echoes the parameter name and gives light context, but it never explains the null default or what theme to pass, leaving the most important semantic detail undocumented.

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 (regions for a theme), which is clearer than the bare name. However, it does nothing to distinguish this from nearby siblings like block_plugin_list, theme_region_create, or layout_builder_sections_list, so an agent must infer the boundary on its own.

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?

There is no indication of when to use this tool versus alternatives, no prerequisites, and no mention of what the optional theme argument does when omitted. The agent gets a purpose but no routing guidance.

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