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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds one genuine behavioral fact beyond the annotations: the result indicates which theme is currently active. It says nothing about ordering, pagination, or how much detail per theme is returned.

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?

Two short sentences, zero filler, with the core action front-loaded and the useful output hint immediately after. Nothing in it is redundant with the title.

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 read-only listing tool with a fully documented single parameter and no output schema, this is nearly sufficient; annotations carry the safety profile. The only meaningful gap is not clarifying the relationship to wp_get_theme and wp_activate_theme in a sibling set where naming is very similar.

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 100% and the single site_id parameter is fully documented in the schema, so the baseline of 3 applies. The description adds no syntax, defaulting, or multi-site behavior beyond what the schema already states.

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 and resource ('List all installed WordPress themes') and adds the distinguishing detail that the active theme is flagged. It is clear what the tool does, but it never contrasts itself with the closely named sibling wp_get_theme, so an agent must infer that this one returns the whole collection rather than a single theme.

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 explicit when-to-use guidance, no exclusions, and no reference to alternatives such as wp_get_theme (single theme) or wp_activate_theme. The agent must derive the selection logic purely from the name and the word 'all'.

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