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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world behavior, so the safety profile is covered. The description adds that the tool returns recent check-in history, which is useful return-behavior context, but it does not explain how much history, ordering, pagination, or any other operational nuance.

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 well-formed sentence with no filler and front-loads the action and resource. Every word earns its place.

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 read-only tool with full schema coverage and rich annotations, the description gives enough context to select and call it correctly, including a high-level statement of returned content. It falls short only in not clarifying what 'recent' means or how the history is structured, which is somewhat relevant because no output schema exists.

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?

Parameter schema coverage is 100%, and both logId and heartbeatId are documented directly in the schema. The description adds no parameter-level meaning beyond the schema, so the baseline of 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 uses a specific verb (Get) and resource (heartbeat) and scopes it to a specific heartbeat, clearly distinguishing it from the sibling heartbeats_list tool. It also states what the return includes: detailed information and recent check-in history.

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 phrase 'for a specific heartbeat' implies the tool should be used when the caller already has a heartbeat identifier, but there is no explicit when-to-use guidance, exclusion, or named alternative such as heartbeats_list. Usage must be inferred from the purpose statement.

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