List themes

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

Annotations already cover the read-only/idempotent safety profile, and the description goes well beyond them: no pagination, broken themes (folder without style.css) are silently omitted, and the subtle active-flag semantics where a parent of an active child theme reports false. That last detail is exactly the kind of non-obvious behavior an agent cannot infer from structured fields.

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?

Front-loads the capability ('all in one answer') in the first clause and then packs return values into a single dense sentence. Every clause carries information, though the return-value sentence is lengthy enough that it would benefit from being split for scanability.

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?

With no output schema, the description carries the return-shape burden and does so fully: per-theme fields (slug, name, version, active), slug format for collection themes, exclusion of broken themes, and the capability gate. An agent has everything needed to call this and interpret the result.

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 takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a parameterless tool applies. The description correctly spends no space restating an empty schema.

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?

Opens with a specific verb+resource ('List the installed themes') and immediately distinguishes its scope with 'all in one answer (no paging)'. It is clearly separable from siblings such as wp_list_plugins and wp_get_update_status, which it explicitly hands off to.

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?

Gives concrete selection context: use this for the full unpaged inventory, and use wp_get_update_status for pending theme updates. It also states the capability prerequisite (edit_theme_options). It stops short of explicit when-not-to-use framing, but the routing to the update-status sibling covers the main ambiguity.

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