Update a To Do task

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

Beyond the annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=false), the description discloses important behavior: omitted due/reminder fields are preserved, clearing requires dedicated flags, and date-time values are sent as Graph dateTimeTimeZone objects with a default UTC timeZone. This meaningfully explains how the patch behaves without contradicting the annotations.

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, each earning its place: the first states the core operation and return value, the second explains partial-update and clearing behavior, and the third clarifies the date-time serialization and timezone default. No filler or repetition of schema details.

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?

Given 11 parameters, no output schema, and annotations covering safety/idempotence, the description plus schema is complete enough for correct invocation. It explains patch semantics, clearing behavior, timezone handling, and the return value ('returns the updated task'), leaving no critical gap for an agent deciding how to call it.

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, but the description adds crucial semantics that the schema alone does not make obvious: omitting dueDateTime/reminderDateTime leaves existing values untouched, clearing requires separate boolean flags, and timeZone governs how wall-clock values are interpreted. This is genuinely additive value.

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?

The description opens with 'Patches an existing To Do task and returns the updated task,' which names a specific verb, resource, and operation style. It clearly distinguishes this from todo_create_task, todo_delete_task, and todo_complete_task, and the status enum even points to todo_complete_task for the common completed case.

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 description gives clear patch semantics ('Only the supplied fields change') and explicit guidance for clearing fields via clearDueDateTime/clearReminderDateTime. The schema adds a direct alternative recommendation for todo_complete_task when setting status to completed, though the tool description itself does not fully enumerate when to prefer this tool over all sibling update/create paths.

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