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

Annotations already declare the safety profile (readOnlyHint, destructiveHint=false, openWorldHint=false), and the description adds genuine context beyond them: the full return shape, pagination fields, default status filtering, and the important semantic that a single block can be embedded in many posts simultaneously. The "server marks it read-only, so it runs straight away" line usefully explains proxy gating behavior rather than merely restating hints.

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 identity, then filters, then return shape, then caveats — a sensible ordering with almost no wasted text. The return-shape sentence partly duplicates the empty output schema budget worth of information, and the closing "Through Royally" clause is slightly awkwardly worded but still earns its place.

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 list tool with no output schema, the description supplies the return structure, pagination semantics, default filter behavior, and the cross-post sharing caveat — enough to call and interpret results correctly. Only the sibling disambiguation is missing.

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 schema already documents every parameter including enum and max bounds; the description restates search/status/per_page/page with their defaults but adds no new syntax or edge-case meaning. It also omits site_id entirely, so this is baseline, not enrichment.

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?

Specific verb + resource: "Lists all reusable blocks") plus the identifying details (synced patterns / wp_block post type), so an agent knows exactly which entity this returns. It does not, however, differentiate from close siblings such as royal-mcp__wp_list_synced_patterns and mcp-easy-ai__wp_list_patterns, which appear to cover the same underlying data.

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 implied by the "reusable blocks are shared across posts" note, which hints at a legitimate reason to list them, but there is no explicit when-to-use or when-not-to-use guidance and no pointer to alternatives (get-block, list-block-types, list-patterns). The agent must infer routing from the name alone.

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