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

Annotations already declare this as a safe read (readOnlyHint=true, openWorldHint=false), so the bar is lower. The description adds genuine context beyond the annotations: results are ordered newest-first and private monitors need the manage_token for authorization.

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 compact sentences with the core purpose front-loaded and the auth caveat second. Every clause carries information; no filler.

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 simple read tool with no output schema and fully documented parameters, the description covers purpose, ordering, and the one non-obvious prerequisite. It omits anything about result volume or paging beyond the limit default, but nothing essential is missing.

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 100%, so the baseline is 3, but the description adds meaning the schema lacks by explaining *when* manage_token is required (private monitors), rather than just that it is the token returned once by create_monitor.

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?

States a specific verb (List) and resource (heartbeats for a monitor) with ordering scope (newest first). No sibling tool overlaps with heartbeat listing, but the description never names an alternative or explicitly distinguishes itself from the monitor CRUD 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?

Gives one clear conditional prerequisite: private monitors require manage_token. However, it offers no alternatives to choose from and no when-not guidance, leaving usage only implied for the general case.

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