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

Annotations only declare destructiveHint=true, so the description carries most of the burden and does add real value: partial-update semantics (unsent fields are untouched), reversibility via a follow-up update, and the constraint that the hidden deleted/spam status cannot be set. It stops short of permissions, audit effects, or status-transition rules, so not a 5.

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?

Four tight sentences, no filler. The scope read comes first, followed by merge semantics, reversibility, and the one hard constraint, with the HTTP endpoint trailing as reference.

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-parameter mutation tool with no output schema and only a destructiveHint annotation, the description covers merge behavior, reversibility, and the main constraint. Gaps remain around permissions and whether status changes trigger notifications, but nothing needed to invoke the tool correctly is missing.

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%, so the baseline is 3. The description adds meaning beyond the schema in two places: it clarifies that omitted parameters are left unchanged (critical for a PUT-style endpoint) and that the hidden status is not settable, which reinforces the status pattern constraint.

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 ("Change a ticket's ...") and enumerates the exactly-updatable surface: subject, status, assignment, department, organization, urgency, hold state, labels. An agent can immediately distinguish this from deskpro_create_ticket or deskpro_add_ticket_message 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?

"Only the fields you pass are sent" and "Reversible by updating again" give useful operational context, and the hidden-status exclusion is a soft when-not. However, no alternative is ever named (e.g., reply via deskpro_add_ticket_message, read via deskpro_get_ticket), so the agent must infer when this tool beats its siblings.

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