tip_calculator

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

With no annotations provided, the description carries the full burden. It discloses the cost ($0.001 USDC), which is a useful behavioral trait, but does not mention side effects, auth requirements, safety profile, or what happens on invalid input. The tool appears read-only, but this is not stated.

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 very concise and well-structured: two short sentences, one stating the tool identity and the other stating the cost. No unnecessary wording. It loses a point because it is under-specified, but that's more relevant to completeness than conciseness.

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 calculator tool, this description is incomplete. It does not explain how to invoke it, what parameters to pass, what the output looks like, or any constraints. With no annotations and no output schema, the agent is left without enough information to use the tool correctly.

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 input schema has a single generic 'params' object with a non-descriptive description, yet schema coverage is reported as 100%. Per rubric baseline, the description is not obligated to detail parameters, but it does not add any semantics either. The description doesn't mention what inputs the tip calculator expects, so it offers no value beyond the schema.

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 identifies the tool as a tip calculator, which is specific and self-explanatory. However, it lacks a verb phrase and does not explicitly distinguish itself from other calculator tools beyond the name, so it falls short of a 5.

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 no guidance on when to use this tool versus alternatives, no context on typical use cases, and no exclusions. It only mentions the category and cost, leaving the agent without decision criteria.

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