To Do & Planner

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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the default no-parameter mode returns task lists, and the planner mode is scoped to tasks assigned to the user, which the annotations cannot convey. It stops short of covering pagination limits or whether include_completed defaults are honored across modes.

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 tightly packed sentences with no filler, and the core capability is front-loaded before the mode-by-mode breakdown. Every clause carries routing information an agent needs.

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?

With four optional parameters, 100% schema coverage, and no output schema, the description supplies the mode-selection logic that the flat schema cannot express. It is complete enough to call correctly, though it could note result caps or that completed tasks are excluded by default, which the schema mentions but the description does not reinforce.

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 schema already documents count, list_id, planner, and include_completed individually. The description mostly restates the schema semantics for list_id and planner, adding only the implicit no-parameter default, so baseline 3 is appropriate.

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 a specific verb and resource ("Read Microsoft To Do and Planner tasks") and then spells out the three distinct retrieval modes, so an agent knows exactly what this tool returns. It does not name any sibling tools, but the resource pairing with Planner/To Do is distinct enough within Microsoft 365 context signals to avoid confusion with ms_calendar or ms_schedule.

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 gives explicit conditional routing among its own modes (no parameters → task lists; list_id → tasks in that list; planner=true → Planner tasks). What it lacks is guidance on when to reach for this tool versus adjacent siblings such as ms_calendar or ms_schedule, so the usage context is clear but not exhaustive.

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