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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds useful behavioral context by naming the status values and clarifying that owner_email indicates whether owner emails currently reach the owner, but it does not discuss auth, pagination, or error behavior.

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 a single front-loaded sentence that lists the returned information without filler. It is slightly awkward as a fragment rather than a complete statement, but every item appears relevant.

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-only status tool with a fully described two-parameter schema and no output schema, the description covers the key returned fields and important status values. It is largely complete, though it could say more about the overall response shape or pagination if applicable.

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 both instance_id and passport_token are already documented in the schema. The description adds no parameter-level meaning beyond that, which meets the baseline for fully documented parameters.

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 title supplies the verb ('Show') and the description names the specific resource and returned fields, making it clear this retrieves heartbeat check status. It is reasonably distinguishable from heartbeat_add/remove/update, though it does not explicitly name siblings or contrast with uptime_status.

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?

There is no explicit when-to-use guidance, no exclusions, and no mention of alternatives such as uptime_status or heartbeat_test. Usage is only implied by the read-oriented field list.

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