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

The description states the tool is a read-only health check ('Health of the MECHANICAL layer'), consistent with readOnlyHint=true and destructiveHint=false. It adds context about having no parameters and implies a lightweight status check. However, it doesn't detail success/failure behaviors (e.g., what happens if layer is down), though the presence of annotations reduces the need for the description to restate safety.

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, front-loads the purpose, and wastes no words. The only minor flaw is the redundant clarification about per-layer reporting, which, while useful for disambiguation, could have been condensed without losing meaning.

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 zero-parameter, read-only status tool, the description is complete: it names the layer, hints at response fields, and clarifies scope (per-layer, not per-server). The sibling tools and annotations fill in the rest. A slightly more complete description might mention the output format (e.g., JSON structure), but given the tool's simplicity, this is nearly complete.

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?

With zero parameters and 100% schema coverage (the schema is essentially empty), the description has no parameters to explain. It correctly focuses on what the tool returns and its purpose, which is exactly what an agent needs. The description's mention of 'load errors' and 'signal counts' hints at the response structure without needing a formal schema.

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 states what the tool does: reports health of the MECHANICAL layer (profiles loaded, signal counts, errors). It differentiates from siblings by explicitly noting this is one per layer and distinguishes from the 'same server' interpretation. However, it does not name any sibling tool (like mechanical_get_robot) for direct comparison.

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 implies this is the mechanical layer's equivalent of hardware/software status tools, but it doesn't explicitly say 'use this when you need mechanical layer health' or specify when NOT to use it. The 'one status tool per layer' comment gives context but no explicit alternative naming.

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