update_action_item

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

Annotations already indicate mutation (readOnlyHint=false, destructiveHint=true). The description adds crucial partial-update semantics (omitted fields are left unchanged), the return shape (same as `get_action_item`), and how to source the id. This goes beyond the annotations and is not contradictory.

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 well-structured with clear section labels (USE WHEN, USE INSTEAD, FIRST, EXAMPLE, RETURNS). Each section earns its place, the main purpose is front-loaded, and there is no unnecessary repetition or 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 mutation tool with five parameters and no output schema, the description covers the purpose, usage context, prerequisites, partial-update behavior, and return format. It also names the sibling to avoid confusion. No critical information is missing for correct invocation.

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 80% (4 of 5 parameters have descriptions). The description reinforces the key rule that only fields to change need be sent, and the example clarifies the structure. It adds a general principle the schema does not fully articulate, elevating it above the baseline for high coverage.

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 states a specific verb ('Change'), the resource ('an action item'), and lists the mutable fields (title, notes, assignee, due date). It explicitly distinguishes this from the sibling `set_action_item_status`, making the tool's purpose unambiguous even without opening the 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?

Provides explicit 'USE WHEN' and 'USE INSTEAD' sections, clearly stating when to use this tool and when to use the alternative for status changes. It also instructs the agent to obtain the `id` from `list_my_action_items` first, a concrete prerequisite that prevents errors.

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