cronometer-mcp

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool returns recent values but doesn't specify what 'recent' means (e.g., last 24 hours, last 7 days), whether it's read-only (implied by 'Get'), authentication needs, rate limits, or error handling. This leaves significant gaps in understanding the tool's 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 highly concise and well-structured: the first sentence states the purpose, and the second elaborates on the returned data with specific examples. Every sentence adds value without redundancy, making it easy to scan and understand quickly.

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 tool has 0 parameters, an output schema (implied by 'Has output schema: true'), and no annotations, the description is minimally adequate. It explains what data is returned but lacks context on recency definition, data format, or error cases. The output schema may cover return values, but the description could better address behavioral aspects for a read operation.

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 0 parameters with 100% description coverage, so no parameter documentation is needed. The description appropriately doesn't discuss parameters, focusing instead on the returned data. This meets the baseline for tools with no parameters, as it avoids unnecessary details.

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 the tool's purpose: 'Get the most recently logged biometric entries from Cronometer.' It specifies the verb ('Get') and resource ('biometric entries'), and lists examples of biometrics returned (weight, blood glucose, etc.). However, it doesn't explicitly differentiate from sibling tools like 'get_daily_nutrition' or 'get_fasting_history', which reduces clarity on when to use this specific tool.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing logged biometrics), exclusions, or comparisons to siblings like 'get_daily_nutrition' (which might overlap in data). Without such context, an agent must infer usage based on the tool name alone.

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