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

Annotations already declare destructiveHint=true, idempotentHint=false, openWorldHint=true, so the safety profile is partly covered. The description still adds real value: the assignee requirement (an unassigned task never surfaces in the planner), the mandatory xtiles_get_current_user lookup, and the warning that the result carries no link so the agent must not fabricate one. However, for a batch multi-item create it says nothing about atomicity (what happens if one task in the array fails), duplicate-creation risk despite non-idempotency, or permission requirements.

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?

The core action and its scope lead the text, and the alternative routes follow in a logical order. It runs long and repeatedly circles back to the tile-vs-task distinction, but given four competing destinations (own planner, checklist tile, project page, project task list) the length is largely earned.

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?

An output schema exists, yet the description still supplies the one return-value fact the schema cannot convey — that no link is returned, so tasks should be reported by title and due date. Combined with the prerequisite user-lookup step and the project routing rule, an agent has everything needed to call this correctly.

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%, so the schema already documents due-date formats, priorities, and assignee id/email. The description nonetheless adds decision semantics the schema cannot express: projectId changes which task list the task lands in, and assignees should default to the current user when unspecified. That is meaningful guidance beyond field documentation.

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 ('Create one or more tasks') plus the crucial scope qualifier ('in the person's own task list'). It explicitly demarcates itself from sibling routes — checklist-into-a-tile (xtiles_create_tiles_from_markdown_in_my_planner) and project-page tasks — so an agent can pick it without opening another 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?

Gives explicit routing rules: use here for the person's own tasks with planner language, use a tile for take/buy lists or instruction steps, do not use this tool for projects, and pass projectId only on explicit request. Both when-to-use and when-not-to-use are spelled out with named alternatives.

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