create-planner-task-message

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

Annotations already indicate destructiveHint=true (mutation). The description adds that it is a beta API subject to change, requires no ETag/If-Match, and has specific auth/permission limitations. It does not disclose rate limits or what gets destroyed, but the creation operation is clearly described.

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 description is front-loaded with the core purpose and tip. It includes a clear body format example. It is slightly long but each section adds useful information. Could be more concise by merging some lines, but remains well-structured.

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?

No output schema is provided, so the description should explain the return value. It only says 'Create a new plannerTaskChatMessage' without mentioning that the created message object is returned. For a write tool with no output schema, this is a significant gap. Also missing details about error handling or idempotency.

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 75%, meaning three of four parameters are described in the schema. The description adds value by simplifying the body structure (content and optional mentions) beyond the lengthy schema, and clarifies that mentions are optional. It does not cover includeHeaders/excludeResponse, but those are standard parameters.

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 ('Create a new plannerTaskChatMessage'), the resource (plannerTask), and distinguishes it from the legacy comment system. The tip explicitly differentiates from the deprecated conversationThreadId approach, and the beta notice adds clarity about the API status.

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 provides clear context on when to use this tool (modern task chat vs legacy comments) and includes important usage constraints (delegated work/school accounts only, no personal Microsoft, no GCC/DoD). However, it does not explicitly list when not to use it or alternatives beyond the legacy comment mention.

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