Create Planner Note

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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false and openWorldHint=true, so the mutation profile is covered. The description adds genuinely non-structured context: where the note surfaces (Canvas To Do list and calendar) and its visibility scope ("Only you see it"), which matters for a user deciding whether to post a task there. It does not address retry/non-idempotency or whether course_id changes visibility.

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 short sentences, zero filler, with the core action and a concrete example front-loaded and the visibility caveat last. Nothing in it is redundant with the name.

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 four-parameter creation tool with full schema coverage and no output schema, the description covers purpose, example content, visibility and where the result appears. Only gap is sibling disambiguation against other create/personal-item tools in the list.

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 every parameter is already documented including the ISO 8601 format for todo_date and the numeric course_id. The description adds a useful content example for the title field but nothing about details or the effect of omitting course_id, so it sits at the baseline.

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 ("Add a to-do note to your Canvas planner") and includes a concrete example note. It conveys the artifact's nature – a personal to-do – but never names the closest sibling (create_personal_event) or clarifies how a planner note differs from a calendar event or bookmark.

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 rather than stated: the example ("Email Prof. Lee about the extension") shows the intended personal-task use case, and "Only you see it" hints at when this is preferable to shared course content. There is no explicit when-not guidance or routing to alternatives like create_personal_event or create_bookmark, which sit in the same sibling list.

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