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

Beyond the annotations (which only hint it is a non-destructive write), the description discloses cost ($0.01 per call, waived on failure), default requester non-notification, the acknowledgement source inbox, and reply-routing behavior. This is substantial behavioral context an agent would not otherwise have.

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?

Three sentences, purpose front-loaded, with the alternative routing and cost appended. Dense but each clause carries information; could be marginally tighter but no wasted padding.

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 10-param mutation tool with no output schema and thin annotations, the description covers cost, notification behavior, and inbox routing well. It omits what a successful call returns (ticket ID/handle) and any inbox-connection prerequisite, which are meaningful gaps but not fatal.

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 only 40%, so the description must compensate. It richly explains email_requester's effect and reply routing, but leaves email, message, name, category, and priority unexplained (priority only has an enum in schema). Helpful for one param but gaps remain for others.

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 support ticket for a customer request', and distinguishes it from ticket_connect_inbox (which opens tickets automatically from emails). It does not explicitly differentiate from chat_create_ticket, but the ticket_-namespace and manual-creation framing make the intent clear.

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 parenthetical 'email to a support inbox opens one by itself; see ticket_connect_inbox' tells the agent when not to use this tool, and points to the alternative. It also notes the email_requester conditional, giving a clear context for use, though it stops short of stating prerequisites like a connected inbox.

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