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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=true. The description adds useful behavioral context beyond that: the note is private, appears in the Order Notes column of exports, does not reach the customer, runs without confirmation, and requires the user's Cotlet API key.

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 front-loaded and readable, but repeats the same idea three times: 'Only you see it', 'only visible to you', and 'reaches no customer'. It could be compressed without losing meaning.

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 add-note tool with full schema coverage and present annotations, the description covers purpose, visibility, confirmation behavior, and auth requirements. It only misses explicit alternatives, which is a minor gap.

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% for both parameters (order_id and note), so the schema already documents them. The description adds no syntax, format, or ordering details beyond what the schema provides.

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 title 'Add order note' and description 'Private note on an order' together make the verb+resource clear, but the description itself is a nominal fragment and does not explicitly say 'adds'. No sibling Payhip tool competes for 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 internal use by stating 'Only you see it' and 'reaches no customer', which hints at when to choose this over customer-facing communication. However, it gives no explicit when-to-use vs alternatives and no exclusions.

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