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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true, and the description adds real post-annotation context: the note is private (nothing is sent to the customer or anyone else), no confirmation is needed, and a Cotlet API key with app access is required. These are meaningful behavioral facts not derivable from the annotations.

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 opening two sentences are near-duplicates ('Add a note to a customer account' / 'Adds a note to one customer account'), which is wasted space. The genuinely valuable behavioral sentence comes third, so the description is not front-loaded as tightly as it could be.

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 write tool with no output schema, the description covers the key concerns an agent needs: privacy of the note, absence of a confirmation step, and the required credential. Only the lack of any note-content constraints keeps it from a 5.

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 both parameters are documented in the schema (including the find_customer cross-reference for customer_id). The description adds no format, length, or content guidance for the 'text' field, so the baseline 3 applies.

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 a note to a customer account') and the schema ties customer_id back to find_customer. It is unambiguous on its own, but it never explicitly contrasts itself with any sibling tool, so it falls short of the sibling-differentiating 5.

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 a useful invocation cue ('runs without asking first') and notes that nothing is sent externally, which implies a low-risk, fire-and-forget usage. However, it never states when to prefer this over alternatives or any prerequisite ordering beyond the API key, leaving usage largely inferred.

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