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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is known. The closing sentence ('its server marks it read-only, so it runs straight away') largely restates that, adding only the practical detail that no approval step intervenes; there is no disclosure of payload size, whether paths shift between reads, or depth-related output 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?

Three short sentences with the return shape and the path example front-loaded, followed by the call-ordering rule. The final 'Through Royally' sentence is the weakest, partly re-stating annotation data, but it is short enough not to bloat the definition.

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 no output schema, the description does the necessary work by naming the return value (parsed block tree with index paths) and its intended follow-up use. Parameters are fully covered by the schema; only secondary details like response size or staleness across sequential edits are absent.

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 post_id, depth and site_id are already documented in the schema, including the omit-for-full-tree default. The description adds no parameter-level meaning beyond that, so 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: returns a post's parsed block tree annotated with an index path per block, plus a concrete example ([2,1]). That path detail is distinctive, though the description never explicitly contrasts itself with near-neighbours like get-page-structure or list-blocks, which an agent would have to disambiguate on its own.

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 an explicit sequencing rule — call this immediately before update-block/remove-block/move-block to obtain current paths — naming the alternative operations and the condition that selects this tool. This is exactly the when-to-use guidance an agent needs for path-dependent mutations.

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