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

Annotations already indicate a write operation (readOnlyHint=false) and idempotency (idempotentHint=true). The description adds the account connection requirement and the confirmation step, which go beyond annotations. No contradiction exists.

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: purpose, prerequisite+confirmation, and account requirement. Information is front-loaded and no fluff.

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 mutation tool with no output schema and annotations covering safety, the description includes prerequisites, confirmation, and authentication. It could mention side effects (e.g., task status change) but that's implicit from the purpose. Adequate completeness for its complexity.

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 100% with descriptions for all parameters. The description reinforces the source of taskId (from list_my_wedding_tasks) but adds little for note or weddingId beyond schema. Baseline of 3 is appropriate since schema handles the semantics.

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 clearly states the action: 'Mark a task on the couple's Wedyesday checklist as done.' It specifies the resource (task on checklist) and distinguishes from siblings like add_my_wedding_task (which would add a new task). The mention of getting the task id from list_my_wedding_tasks also differentiates its use 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?

It provides explicit prerequisite: 'Get the task id from list_my_wedding_tasks first' and advises confirming with the couple which task they mean. It also notes the account requirement. Although it doesn't explicitly contrast with alternatives, this guidance is clear enough for correct usage.

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