mfp_set_measurement

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

Annotations already establish that this is a non-read-only, non-idempotent, non-destructive operation. The description adds that it records a value in MyFitnessPal and returns a confirmation, but it does not clarify whether repeated logging of the same measurement creates duplicates or overwrites an existing entry — a meaningful side-effect for a 'set_measurement' tool.

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?

Short and front-loaded, with clearly labeled Args and Returns sections. The second sentence is somewhat redundant with the first, but overall the structure is efficient and scannable.

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?

The description covers the action, key inputs, and return type, and the annotations plus nested input schema fill in the safety and parameter details. The main missing pieces are duplicate/overwrite behavior and a richer list of valid measurement types, but these do not block correct invocation for the common case.

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 description lists both parameters with a default and an example, which is helpful given the low schema description coverage signal. However, it does not enumerate valid measurement type strings or specify units beyond the 185.5 example, so some inference is still required.

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?

Begins with 'Log a new body measurement...' — a specific action, object, and time scope ('for today'). This clearly distinguishes it from sibling read tools like mfp_get_measurements and from goal/water/food tools.

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 explicitly states when to use the tool: to log a new body measurement for today. It does not mention exclusions or point to alternatives such as mfp_get_measurements for retrieving measurements, but the intended use is clear enough for correct selection.

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