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

With only a minimal annotation (title), the description carries the behavioral disclosure burden. It honestly states that the note persists 'next conversation' and that writing an existing title rewrites that note. This surfaces the key mutation and idempotency traits. However, it does not mention return format, failure modes, or permissions, so a perfect score is not warranted.

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?

The description is exactly two short sentences. The first establishes the primary function and persistence; the second clarifies the overwrite rule. Every word contributes, with no filler or repetition of schema details.

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 simple two-parameter tool with no output schema, the description covers the essential behavior: creation, persistence, and overwrite-on-existing-title. It does not mention return values or error handling, but given the tool's simplicity and rich schema, the context is sufficiently complete for correct invocation.

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%, and the title parameter's description already contains the rewrite behavior. The main description adds only general context ('under a title', 'next conversation') without new parameter semantics. Since the schema handles parameter explanation, a baseline 3 is appropriate.

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?

The description opens with a specific verb and resource ('Write a note under a title'), clearly indicating the tool's core action. It also explains the overwrite behavior, which distinguishes it from sibling tools like notes_get, notes_list, and notes_delete by covering both creation and update via the same action.

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?

The description implies when to use the tool: to persist a note for future conversations and to overwrite an existing note by reusing a title. It does not explicitly name alternatives or exclusions, but the context is clear enough for an agent to select it over read/delete siblings.

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