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

Annotations already declare destructiveHint=true, idempotentHint=false and openWorldHint=true; the description adds substantial context beyond them — no undo point is recorded, an existing theme folder is not overwritten and WordPress's error is surfaced instead, and the return shape (installed, stylesheet, version) is spelled out. These are exactly the side effects an agent needs to know before a destructive install.

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?

Purpose and scope lead the sentence; each following clause carries distinct, non-redundant information (return values, permission, refusal mode, no-undo, overwrite behavior, alternatives, routing). Dense but nothing is padding.

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 one-parameter destructive install with no output schema, the description covers preconditions, failure modes, side effects, return fields, and sibling routing — everything needed to invoke it correctly 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?

Schema coverage is 100% and the schema itself documents slug format, lower-casing, and character stripping in more detail than the description. The description only restates 'by its slug', adding no semantics beyond the structured field, so the baseline 3 applies.

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 (download and install a theme), the source (WordPress.org directory), the keyed selector (by slug), and a critical scope qualifier (the theme is not activated). This separates it cleanly from wp_activate_theme and the ZIP-install path without the agent needing to open either schema.

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?

Names explicit alternatives and the conditions that select them: ZIP sources go to wp_install_theme_zip, switching themes goes to wp_activate_theme. It also states preconditions (needs install_themes) and the refusal condition (DISALLOW_FILE_MODS), so an agent can decide before calling whether the tool will even succeed.

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