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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety and idempotency profile is carried by structured data, and an output schema exists so return values need not be described. The description adds only the create-vs-update distinction and the "private" attribute; it does not explain replay semantics of idempotencyKey, what happens on key collision, or any limits beyond those in the schema.

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?

A single compact sentence that front-loads the use condition and then the alternative, with no filler or repetition of schema/annotation content. 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?

With full param coverage, rich annotations and an output schema, the description needs only to establish purpose and routing, which it does. The one residual gap is the unresolved "private note" vs. "household note"/personRefs tension, which an agent could misread when deciding whether to attach people.

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%, with title, tagNames, personRefs, bodyMarkdown and idempotencyKey all documented in the schema, so the baseline is 3. The description contributes no additional parameter meaning — notably nothing about tag replacement behavior or how personRefs should be sourced — beyond what the schema already states.

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 ("create a private Markdown note") and names the sibling it is not (update_note), so an agent can distinguish it without opening schemas. The only softness is the qualifier "private," which sits oddly against the title "Create Household Note" and against the schema's personRefs/"shown to the household" fields, leaving mild ambiguity about the note's audience.

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?

Explicitly gives a when-to-use condition (creating a note) and a concrete alternative for the other case ("use update_note with a current version for changes"), which correctly implies this tool is for new notes only. It omits prerequisites an agent would want — e.g., that personRefs come from find_contacts and idempotencyKey must be unique per attempt — but the core routing guidance is clear.

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