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

Annotations declare readOnlyHint=false, destructiveHint=true, and idempotentHint=true, so the description doesn't need to repeat those. The description adds value by clarifying that unspecified fields are preserved, which is a specific behavioral guarantee beyond the annotations. It does not contradict any annotation.

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 with no wasted words. The action is stated first, followed by the critical usage rule. It is front-loaded and immediately actionable.

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?

Given the 21 parameters are fully described in the schema, annotations cover idempotency and destructiveness, and the description explains the partial-update behavior, the tool is adequately specified. It does not mention return values or error handling, but no output schema exists and the operation is straightforward. Minor gaps like return format are not critical for a patch 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?

Schema description coverage is 100%, so each parameter already has a descriptive text. The tool description does not add any parameter-specific meaning beyond the generic 'pass only fields you want to change', which is about usage rather than individual parameter semantics. 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 clearly states a specific action ('Patch a monitor') and the resource (monitor). It distinguishes itself from siblings like create_monitor, pause_monitor, and resume_monitor by implying modification of an existing monitor. The partial-update semantics ('Pass only fields you want to change; others are preserved') adds precision beyond a generic 'update'.

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 explicitly instructs the agent to pass only fields to change, which is the core usage rule. It does not mention alternatives or when-not-to-use (e.g., 'use create_monitor for new monitors' or 'use pause_monitor to toggle pause'), but the partial-update guidance is clear and sufficient for selecting this tool over create_monitor. It lacks explicit exclusions but is not misleading.

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