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

Annotations already provide readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds value by detailing the output: 'returns a brutal verdict, number of pivots required, a funny comparable, a realistic YC rejection reason, and the actual TAM (always $4 trillion)'. This provides context beyond the annotations.

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 one sentence that efficiently conveys the tool's purpose and outputs, with no wasted words. It is front-loaded and easy to parse.

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 lighthearted tool, the description fully sets expectations. The output schema exists (inferred from context), so return values are documented. The description explains the unique TAM value, which is a key behavioral detail.

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% for all parameters, so the schema already documents each parameter. The description does not add further meaning to the parameters; it focuses on the output. Baseline 3 is appropriate.

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 uses the specific verb 'evaluate' with the resource 'startup idea', clearly stating the tool's purpose. It lists the specific outputs (verdict, pivots, comparable, rejection reason, TAM), making it distinct from sibling tools which are more serious and analytic.

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 a humorous, informal use case through terms like 'brutal verdict', 'funny comparable', and 'realistic YC rejection reason'. However, it does not explicitly state when to use this tool versus alternatives, or when not to use it.

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