Read the weight history

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: newest-first ordering, the fact that a limit-only call has no default period and can return very old entries, and the meaning of the direction codes (1 gain, -1 lose, 0 keep). It doesn't discuss pagination or truncation signalling, keeping it short of a 5.

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?

Front-loads the return shape, then the period/limit behavior, then the alternative tool, in a tight sequence with no filler. The parenthetical asides make it slightly dense, but every sentence carries information an agent needs.

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?

An output schema exists, so return values need not be re-explained, yet the description still gives enough about ordering, defaults, and field meaning for correct invocation. With the low-complexity schema (3 optional params) and annotations covering safety, nothing an agent needs is missing.

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 100%, so the baseline is 3, but the description goes further by explaining the fallback semantics of omitting from_date/to_date and how limit interacts with them ('newest entries up to limit, however old'). It also clarifies the unit context (kg unless changed in the app) and the derived fields difference/direction, which the schema does not define.

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?

States a specific verb and resource ('List logged body weights') and immediately enumerates the returned fields {date, value, difference, direction}, so an agent knows both the action and the shape. It differentiates itself from nearby siblings like get_measurement_history and get_report by naming get_report explicitly for the long-period case.

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?

Spells out both branches of use: pass from_date/to_date to select a period, or omit them to get the newest entries up to limit with no default period. It also routes the agent to get_report when the question is change over a long period, which is explicit alternative-selection guidance.

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