hevy_update_body_measurement

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

No annotations exist, so the description carries full burden. It fully discloses the destructive null-overwrite behavior, the dry-run safety mechanism, and the configuration requirement (HEVY_MCP_ALLOW_WRITES). This gives the agent a complete understanding of the tool's side effects and safety constraints.

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 compact yet comprehensive. It starts with the core action, follows with the critical null-overwrite warning, provides a practical pattern for partial updates, and finishes with the dry-run behavior. Every sentence is purposeful and front-loaded for quick comprehension.

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 complexity (nested object, destructive operation, dry-run), the description covers most key aspects. It omits details about the return format beyond the dry-run example and does not mention error handling or authentication prerequisites. However, for a tool with sibling tools that provide additional context, 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?

Schema coverage is 0%, meaning the description must compensate. While it clarifies that body_measurement is an object whose missing fields become null, it does not list or explain individual fields beyond their presence in the schema. The description adds context about the replace semantics but lacks detailed parameter descriptions, so it only partially compensates for the absent schema documentation.

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 it is a 'full replace' of body measurements for a date, using PUT. It explicitly distinguishes from a partial update and explains that unspecified fields are overwritten to NULL, leaving no ambiguity about the operation.

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 explicit guidance: for a partial update, it instructs to first call hevy_get_body_measurement, modify, then send all fields. It also warns about the destructive null-overwrite behavior and mentions the dry-run default and the required environment variable to enable writes, giving clear when-to-use and when-not-to-use advice.

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