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

Annotations already indicate destructiveHint=true, so the description adds value by disclosing partial-update semantics ('Pass only the fields you want to change') and clarifying `done` behavior. It does not contradict annotations, but omits details on irreversible effects or other side effects beyond what schema indicates.

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 two well-structured sentences: the first states the core action and lists updatable fields, the second points to an alternative. No filler or redundancy, fully front-loaded.

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 12-parameter mutation tool with no output schema, the description covers the essential mutable fields, gives usage context, and flags an alternative. It lacks explicit mention of required `board_id` and auth (`access_key`), but those are discoverable from the schema and the tool's broader context.

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 low (33%), and the description compensates by explaining the meaning of key fields: priority values, `done` as completion, `column_id` for reassignment, and sources of `id`. It omits `board_id`, `author`, and `access_key`, but these are more infrastructural than domain-specific.

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 'Update an existing task by `id`' with a specific verb and resource, and explicitly differentiates from `move_task` for column movement with order, making it distinct among siblings.

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 explicit when-to-use guidance (update fields of a task), instructs to pass only fields to change, and names an alternative tool (`move_task`) for a specific scenario, satisfying the when/when-not criteria.

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