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

With destructiveHint=true already declared, the description adds real value by clarifying that omitted fields are preserved (partial update, not overwrite) and that clearDueDate is the explicit mechanism for removing a due date. It does not cover permission/auth requirements or reversibility, so it stops short of full transparency.

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 zero filler; the field list comes first and the patch/clearDueDate behavior follows as the key constraint.

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, the description adequately covers the mutation contract and the one non-obvious flag. The remaining gap is that it never frames the required mailbox/listId/taskId triplet as the addressing scheme, though the mailbox schema partially covers that.

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 carry weight, and it does: it names title, dueDate, importance, notes, status and clearDueDate, i.e. the very fields the schema leaves undocumented, and explains the clearDueDate side effect. It omits any semantic help for the required identifiers (mailbox, listId, taskId) and timeZone.

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 (change/update) and resource (an Outlook To Do task) and enumerates the mutable fields, so the agent knows exactly what surface it touches. It doesn't explicitly distinguish itself from close siblings like complete_outlook_task or update_google_task, but the task-update intent is unambiguous.

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?

Usage is implied by the field list and the patch semantics ('omitted fields are left alone'), which tells the agent this is for partial edits rather than a full replacement. However, it never says when to prefer complete_outlook_task over this tool, nor does it name any alternative or prerequisite beyond the mailbox parameter's own schema note.

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