add_weigh_in

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

There are no annotations, so the description carries the full burden of behavioral disclosure. It only says what the operation does ('Add a new weight measurement') without explaining side effects, whether existing entries are affected, authentication/authorization requirements, or what the response contains. For a mutating tool, this is a meaningful gap.

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 short and front-loaded with the primary purpose. The Args section is concise and directly maps to the schema parameters. It is not overly verbose, though the parameter notes could have been slightly richer without becoming bloated.

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?

For a simple two-parameter tool with an output schema, the description covers the basic operation and parameter meaning. However, it lacks usage guidance and behavioral context, especially the distinction from add_weigh_in_with_timestamps. Given the tool is a mutation with no annotations, this is only minimally 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?

The schema has no descriptions (0% coverage), but the description compensates by explaining each parameter: 'weight: Weight value' and 'unit_key: Unit of weight ('kg' or 'lb').' It adds the allowed unit values, which the schema does not specify. This is useful, though the semantics are still relatively shallow.

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 and resource: 'Add a new weight measurement.' This is clear and actionable. However, it does not differentiate from the sibling tool add_weigh_in_with_timestamps, so an agent could be unsure which one to use for a given scenario.

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 gives no guidance on when to use this tool versus alternatives such as add_weigh_in_with_timestamps, delete_weigh_ins, or get_weigh_ins. There is no mention of exclusions, prerequisites, or typical use cases, so the agent has to infer the appropriate context from the name alone.

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