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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false, so the safety profile is covered. The description adds meaningful behavioral context: CLOUD vs PRIVATE semantics, PRIVATE being the only kind that can reach customer-network hosts, and the ID-reuse warning. It could mention output format or pagination, but that's not critical for a 0-parameter read-only list.

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?

Four sentences, each earning its place: purpose, ID warning, CLOUD/PRIVATE explanation, and relationship to siblings. The core purpose is front-loaded and there is no redundant restatement of the title.

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 parameterless read-only list with rich annotations, this is complete. It tells the agent what the entries mean, how they relate to other tools, and when to consult this endpoint, so no additional context is needed 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?

There are zero parameters, so the schema needs no elaboration. The description compensates by explaining the meaning of the returned entries' types and how the ids are consumed by other tools.

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 and resource: 'List everywhere a Monitor's Cycles can run from.' It distinguishes itself from list_engines by explicitly noting monitoring locations are their own set, not the load test regions list_engines offers.

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 gives explicit when-to-use guidance: 'Read this before create_monitor or update_monitor.' It also warns against inventing IDs, tells the agent these IDs are what engineIds names, and names the sibling list_engines as offering a different set.

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