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

With no annotations, the description carries full burden. It conveys this is an informational read (reporting actions taken/queued) without explicit side-effect disclosure. It adds value by clarifying the scope (recent and pending), but does not go into detail about ordering, limits, or response format. Since the tool name and wording strongly imply a safe read-only operation, a mid score is appropriate.

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 two sentences. The first sentence states the core content (what it returns), and the second provides the usage trigger. Every word earns its place, with no fluff or repetition of the schema.

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?

Given the zero-parameter signature and lack of output schema, this description covers the essential context: what data is returned and when to use it. It could potentially mention the format or structure of the actions, but for a simple list-like tool, the existing description is largely sufficient.

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?

The tool has zero parameters, so the description does not need to explain parameter syntax. The baseline for 0-param tools is 4, and the description appropriately focuses on use case rather than parameter details, which is sufficient.

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 clearly identifies the tool as reporting 'recent and pending self-healing actions' taken or queued by the system. It distinguishes itself from broader health/status tools by focusing specifically on self-healing actions, making its purpose unambiguous.

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 description explicitly states when to call: 'when the user asks whether the system/data pipeline is healthy or why data looks missing/stale.' This provides clear context, though it does not name alternative tools (e.g., tengu_status, tengu_v3_system_health) for comparison, so it lacks explicit exclusions or alternatives.

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