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

Annotations already mark the operation as non-read-only and non-destructive, so the description's 'Log' phrasing does not add safety information beyond what is structured. It also does not disclose side effects such as writing to a Garmin destination or whether repeated calls create duplicates, though the openWorld/idempotent hints partially cover this.

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 a single, front-loaded sentence with no filler: 'Log body weight in kilograms.' Every word adds semantic value, and there is no duplication of schema content.

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 schema richly documents all parameters and an output schema exists, covering call mechanics and return values. However, the description lacks high-level context about destination selection or when this tool is preferred over sibling tools, so an agent has to infer intent from the tool name and schema alone.

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 description coverage is 100%, so all six parameters are documented in the schema. The description only mentions 'kilograms' and does not add meaning for account, timestamp, destination_id, destination_kind, or user_query_context; baseline 3 applies because the schema carries the semantic burden.

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 states a specific verb ('Log'), a precise resource ('body weight'), and the unit ('kilograms'), which clearly identifies the tool's function. It is not a tautology because it clarifies 'body mass' as 'body weight in kilograms,' but it does not explicitly distinguish itself from sibling logging 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 implies the tool should be used when a body-weight value needs to be recorded, but it names no alternatives (e.g., log_nutrition, log_water) and gives no explicit when-to-use or when-not-to-use conditions. The intended context is inferable from the resource type, but not stated.

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