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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true), and the description adds real context beyond that: notes are never shown to the client, no confirmation is needed, and a Cotlet API key with app access is required. This is meaningful behavioral disclosure, though nothing about rate limits or response shape is given.

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?

Purpose is front-loaded, but the description repeats itself: the client note's visibility ('shown at booking and checkout') is described twice in near-identical terms, and 'Adds an internal note to a client profile' restates the opening clause. It is not bloated, but it could lose a sentence with no information loss.

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 three-parameter mutation with full schema coverage, no output schema, and annotations present, the description covers purpose, note-type semantics, auth requirements, and confirmation behavior. It is essentially complete, with only minor redundancy rather than missing information.

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 coverage is 100%, so the baseline is 3, but the description adds genuine meaning to the 'kind' enum by explaining what a client note does versus what a timeline note is. It also reinforces that the note text is internal, adding intent beyond the schema's own wording.

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 states a specific verb and resource ('Add an internal note to a client') and immediately distinguishes the two modes of the resource: a client note surfaced at booking/checkout versus a dated timeline note. An agent can tell exactly what this tool does and how it differs from the sibling timeline/list tools.

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?

It gives clear context for the two note types and notes that the operation 'runs without asking first,' which tells the agent no confirmation is required. It never names an alternative tool or states explicit exclusions, so it stops short of full when/when-not routing.

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