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

Beyond the annotations (destructive/openWorld/non-idempotent), it discloses concrete behavior: values validated against the block type's attribute definitions, edit-lock check, refusal of changes WordPress would strip for the account, a revision is saved, an undo token is returned, and the call is queued for human approval via Royally so nothing changes immediately. That is exactly the extra context annotations cannot carry.

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-loads the core action, then the qualifying condition, then the refusal/alternatives, then side effects — a logical order. Slightly dense with parentheticals (block examples, site URL, Royally approval note), but nearly every clause 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 destructive nested-object mutation with no output schema, the description covers eligibility, validation, lock/prune behavior, reversibility (revision + undo token) and the approval gate. Nothing an agent needs to call it safely 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 baseline applies. The description restates semantics already in the schema ('null removes an attribute', path sourced from wp_get_block_outline) and adds nothing about expected_name, the guard parameter that most deserves a line of narrative guidance.

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 ('Change attributes of the block at path') and immediately scopes it to blocks that store no markup, naming the sibling that handles markup-storing blocks (wp_replace_block). An agent can distinguish this from wp_replace_block and wp_update_page without opening a 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 the selection condition explicitly ('blocks that store no markup ... server-rendered blocks such as latest posts, query loops'), points at wp_get_block_outline as the discovery step that marks which blocks qualify, and names the alternative (wp_replace_block) for the excluded case.

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