garmin_pace_zones

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, indicating a safe read operation. The description adds behavioral context: it calculates zones using the classic 5-zone model based on threshold pace, and returns the threshold used and zone ranges. No contradictions.

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 concise, front-loaded with purpose, and includes parameter hints and return info. It is efficiently structured with minimal waste, though slightly verbose with the 'Args:' and 'Returns:' formatting.

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 richness of annotations and input schema, the description adequately covers the tool's purpose, parameters, and return value. It explains the fallback behavior and output format, making it complete for an AI agent.

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 already provides descriptions for parameters (threshold_pace format and default behavior, response_format enum). The tool description repeats this info and adds a brief summary. Since schema coverage is good, the description adds marginal value.

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 purpose: estimating running pace zones (Z1-Z5) from threshold pace. It specifies that it uses provided threshold_pace or reads from Garmin lactate threshold, effectively differentiating from sibling tools like garmin_hr_zones.

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 explains when to use the tool: provide threshold_pace or omit to auto-fetch from Garmin. It does not explicitly mention when not to use or compare with alternatives, but the context is clear.

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