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

Annotations already declare readOnlyHint=false, destructiveHint=true, and idempotentHint=false; the description adds what the annotations cannot — that the note is internal-only and never customer-visible, plus the underlying route (POST /messages with type Note). It does not explain why destructiveHint is true or whether notes can be edited/removed later, which is a small remaining gap.

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?

Two short sentences plus a route hint; the 'WRITE' marker and the core purpose are front-loaded. The trailing 'POST /messages with type Note' is slightly implementation-flavored for an agent-facing description but is compact and adds precision, so it 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?

No output schema exists, but the tool only takes two fully-documented parameters and the annotations cover the safety profile, so an agent has what it needs. The only thin spot is the unexplained destructiveHint=true, which the description does not address.

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 both parameters documented (text with length bounds, ticket_id with positivity constraint), so the schema carries the load. The description adds no parameter-level detail such as the 20000-char cap or id format; 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?

States a specific verb+resource ('add an internal note to a ticket') and explicitly scopes it as team-only and never customer-facing, which separates it from sibling edesk_reply_to_ticket and from edesk_add_order_note. An agent can route correctly without opening the schema.

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 line 'for the team only and is never sent to the customer' gives clear context for choosing this over a customer reply, and the 'WRITE' prefix signals a mutation path. It stops short of explicitly naming the alternative tool or stating when not to use it.

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