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

Annotations already declare the write-but-non-destructive, closed-world profile, so the bar is lower. The description adds real value beyond them: the WordPress 6.9+ requirement, thread reply semantics via parent_id, and the resolution rule that the first block containing anchor_text wins.

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?

Two sentences, zero filler, with the create action and version gate front-loaded before the block-location and threading options. Every clause maps to something an agent needs.

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?

Coverage is good for a five-parameter create tool with rich schema and annotations, and no output schema exists so return values need not be explained. The one gap is that it never says whether the new note's identifier comes back, which an agent needs to chain a reply via parent_id.

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 all five parameters. The description mostly restates schema text ('short exact snippet', 'reply to an existing note with parent_id') without adding format, length, or disambiguation rules beyond what is already there; a 3 baseline is correct.

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 ('Add an editor note to a block of a post') plus a version constraint and a concrete UI analogue ('editor's Notes panel'). An agent can tell this creates a block-level annotation rather than a comment or a post edit, even though the nearest sibling wp_update_note is not named.

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 clear invocation context: use anchor_text or block_index to target a block, or use parent_id to reply to an existing thread. It does not route between siblings (e.g., wp_update_note for edits, wp_create_comment for reader comments), so the boundary with alternatives is left to inference.

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