Update a Microsoft To Do Task

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

The critical statement 'Only the fields you provide are changed' discloses partial-update semantics, which is valuable beyond the annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=false). It does not mention error conditions, but the key behavioral trait is covered.

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?

Two sentences convey the purpose, scope, partial update behavior, and an alternative. Front-loaded with the verb and resource, with no filler or redundant information.

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 tool with 7 parameters and no output schema, the description is complete enough: it states what fields can be updated, that it's a partial update, and when to use a different tool. The absence of an output schema is not a gap for a mutation tool.

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?

The input schema already provides 100% parameter coverage with descriptions for every field (title, notes, due_date, importance, status, list_id, task_id). The description merely lists the same fields without adding extra semantic detail, so it adds no value beyond the schema.

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 uses the specific verb 'Update' and identifies the resource as 'an existing task', then enumerates the exact fields that can be modified. This clearly distinguishes it from sibling tools like todo_complete_task, which is explicitly mentioned as an alternative.

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 an explicit alternative: 'To mark a task done, prefer todo_complete_task.' This gives a clear when-not scenario and points to the correct sibling, satisfying the requirement for alternatives.

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