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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the description's 'Read-only' and 'runs straight away' largely restate structured data. It adds the useful signal that results describe Site Editor customisation state, but says nothing about pagination, ordering, or behavior when the theme has no templates.

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 core sentence is front-loaded and dense: verb, resource, and return fields in one line. The trailing '(site: demo.royalplugins.com)' and 'Through Royally: read-only, runs straight away' are redundant filler given the site_id enum and the annotations.

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-required-parameter read-only listing tool with no output schema, the description is nearly sufficient: it names the resource and the fields returned. Missing only guidance on result volume/ordering and the relationship to the single-template getter.

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 coverage is 100% with both parameters documented and enum-constrained, so the schema does the heavy lifting. The description reinforces that both templates and template parts exist (the axis the 'type' filter controls), but adds no syntax or default semantics beyond that.

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?

States a specific verb ('List') and resource ('the block theme's templates and template parts') and enumerates the returned fields (ID, slug, title, area, customised flag). This clearly separates it from the singular wp_get_block_template and from wp_list_block_types/wp_list_synced_patterns siblings.

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?

Usage is only implied: an agent can infer this is the tool for enumerating block theme templates, and the optional 'type' narrowing is described in the schema. There is no explicit when-to-use guidance, no named alternative (e.g. wp_get_block_template for a single template), and no exclusions.

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