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

Annotations declare non-read-only, idempotent, non-destructive, closed-world, but the description adds a genuinely important disclosure not in the annotations: the token is a bearer secret and anyone holding it can report a heartbeat. It stops short of saying what a failure report triggers (e.g., alerting) or how an invalid token is handled.

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?

Three short sentences, front-loaded with the action, then the parameter clarification, then the security caveat. No redundant restatement of the tool name or schema types; every sentence adds information.

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 two-parameter, no-output-schema tool, the description covers the action, the identifier ambiguity, and the security model. Nothing an agent needs to invoke it correctly is missing, and return values need not be described without an output schema.

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 only 50%, with the `failed` boolean having no schema description at all, so the description must compensate. It does so for `token` by disambiguating it from the monitor UUID and locating it in the pingUrl; the success/failure framing implicitly maps to the `failed` flag, though that mapping is never made explicit.

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 and resource: 'Report success or failure for a heartbeat monitor.' This is immediately distinguishable from siblings like create_monitor, pause_monitor, and inspect_monitor, which manage rather than ping a monitor.

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 context for calling it is clear: report a heartbeat (success or failure) for a monitor with a known ping token. No exclusions or named alternatives are given, so an agent must infer that monitor lifecycle operations belong to the create/pause/inspect siblings.

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