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

Annotations provide only readOnlyHint=false, destructiveHint=false, and idempotentHint=false, so the description carries the burden of explaining mutation behavior. The phrase 'Pass only the fields you want to change' clearly discloses partial-update semantics, which is valuable beyond the schema and annotations. It does not describe side effects or return behavior, but the output schema covers return shape.

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 short sentences with no filler. It front-loads the tool's purpose and immediately follows with the critical partial-update instruction, making it easy to parse quickly.

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 six-parameter mutation tool with an output schema and no parameter descriptions, the definition is adequate but not complete. It covers the core update behavior and partial-update semantics, but it omits guidance on when to prefer update_task_state and provides no detail about accepted values for the enumerated-looking string fields. The presence of an output schema reduces the need to describe return values.

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 0%, so the description must compensate. It lists the five updatable fields and clarifies that omitting a field means it should not change, which adds real meaning beyond the nullable schema properties. However, it does not explain the allowed values or semantics of 'state', 'priority', or 'plan_status', leaving some burden on the agent to infer valid inputs.

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 a specific verb ('update') and resource ('task'), and explicitly enumerates the updatable fields: title, body, priority, state, plan_status. Saying 'Full task update' distinguishes this from the more focused sibling update_task_state without needing to open 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?

The description implies this tool is the broad update option versus the narrower update_task_state sibling, but it never explicitly states when to use one over the other. There is no when-not-to-use guidance or mention of alternative tools such as create_task or update_task_state.

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