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

With no annotations provided, the description carries the burden of disclosing behavioral traits. It adds the key detail that no API key is required, which is a behavioral trait. It does not describe the return value or error behavior, but for a simple liveness check, this is sufficient for an agent to understand what to expect.

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: 'Liveness check for the OptionsBell MCP server. No API key required.' Every word earns its place, with no redundancy or filler. It is appropriately brief for a tool of this simplicity.

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 health-check tool with no parameters, no output schema, and no annotations, the description is fully complete. It states the purpose and the absence of authentication requirements, which is all the context an agent needs to select and invoke this tool correctly.

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 input schema has zero parameters (empty properties object), and the description adds no parameter information. Per rubric, a zero-parameter tool receives a baseline of 4, and the description need not compensate since there are no parameters to explain.

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 'Liveness check for the OptionsBell MCP server', specifying both the verb (check) and the resource (server). This distinctly sets it apart from the sibling tools, which are all data retrieval operations (e.g., get_flow_history, get_iv_rank), making the tool's 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 phrase 'No API key required' provides useful context for when to use the tool, implying it can be called without authentication setup. However, it does not explicitly mention when to use it versus alternatives or provide exclusions, though the liveness-check nature clearly suggests using it for connectivity verification before data calls.

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