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

Annotations provide only destructiveHint=true, so the description carries most of the load and does add a genuinely useful behavioral fact: no customer-facing message is emitted on creation. It does not discuss permissions, whether the having an existing contact is validated, or the failure behavior if the contact/channel is invalid.

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 tight sentences with the core action and the critical 'nothing is sent yet' caveat front-loaded, plus the underlying API endpoint. No filler.

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 3-parameter create tool with no output schema and fully documented params, the description covers what an agent needs to act correctly. It leaves the return value (e.g. the new ticket id) unstated, which is a minor gap given no output schema exists.

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 all three parameters, so the schema already documents subject, channel_id, and contact_id. The description only reinforces that the contact must pre-exist; it adds no format, ID-sourcing, or defaulting detail beyond the schema.

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 and resource ('Open a new ticket') and adds the scoping constraint that the contact must already exist and a channel is involved. An agent can distinguish this from trengo_send_ticket_message or trengo_create_contact without opening any 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?

Explicitly explains the relationship with trengo_send_ticket_message, clarifying that creating a ticket alone sends nothing to the customer. It does not name when-not-to-use or alternatives for ticket creation itself (e.g. board cards), so it stops short of full routing guidance.

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