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

Annotations already declare readOnlyHint/destructiveHint=false, and the description reinforces this ('its server marks it read-only, so it runs straight away') while adding non-obvious behavior: theme.presets/theme.styles auto-resolve the stylesheet from the active theme when omitted. Together this gives a solid picture of side effects and defaults, though nothing is said about response size or failure modes.

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-loaded with the resource and operation list, followed by workflow guidance; no filler sentences. The operation enumeration is dense but each entry carries distinct information, so length is justified.

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 annotations covering the safety profile and a 100% schema, the description only needs to explain operation semantics and sequencing, which it does; the per-operation parentheticals effectively hint at the returned content even without an output schema. Minor gap: no note on the shape or volume of 'get' responses.

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%, so the baseline is 3, but the description adds meaning beyond the schema: it defines each operation's semantics, states that theme.presets/theme.styles auto-resolve the stylesheet when the param is omitted, and prescribes the list→describe→get param-discovery flow. That is genuine added value over the enum descriptions.

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 (Query) and resource (site design context), then enumerates four concrete operations with parentheticals describing each (theme.active returns the active stylesheet slug, theme.presets returns palette/fonts/spacing tokens, etc.). The purpose is unambiguous, though it never names a sibling like wp_get_active_theme or wp_get_global_styles to distinguish itself.

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 explicit operational routing: 'Use action "list" to discover operations, "describe" for schema, "get" to fetch data' plus a concrete workflow ('Start with theme.active... then theme.presets') and a design rule ('Use preset slugs instead of hard-coded values'). It stops short of naming alternative sibling tools or when-not to use this.

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