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

Adds value beyond the annotations: publishes the exact return field set including that content is raw Gutenberg markup, and explains that the server marks it read-only so it executes without confirmation. The note about editing a reusable block affecting every embedding post is useful referential context, though it describes the resource rather than this specific read call's behavior.

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?

Four short sentences, front-loaded with purpose and return shape, with the lookup pointer last. The final clause about Royally's read-only marking is slightly awkwardly phrased but still earns its place by explaining approval behavior.

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?

Covers everything needed for a two-parameter read tool with no output schema: precise purpose, discovery path to the required ID, full return field list, and the embedding-by-reference consequence. Nothing an agent needs in order to call it correctly 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 coverage is 100% and both parameters are documented, so the schema already carries the semantics. The description adds nothing about block_id format or what happens with an invalid/nonexistent ID, so the baseline 3 applies rather than a higher score.

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 ('Gets a single reusable block') and immediately disambiguates the terminology ('synced pattern / wp_block'), which matters because sibling tools use both names (wp_list_patterns vs wp_list_blocks). An agent can identify this as the single-item fetch without opening the 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?

Gives concrete routing guidance, 'Use `wp_list_blocks` to find the ID', which is a real sibling. It does not state exclusions, e.g. when to prefer opening the parent post or wp_get_post_blocks instead, so it falls short of explicit when-not guidance.

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