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

Beyond the annotations (which only indicate non-read-only, non-destructive), the description discloses key behavioral traits: applying commits neither side, nothing is charged, terms are agreed in writing before any registration/launch/spend, human review occurs, replies go to the given email, and the call is refused below the ET10 holding. This significantly exceeds what structured fields provide.

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 dense paragraph with four sentences, all carrying critical information: purpose, terms/commitment, human review, and the ET10 requirement. It is front-loaded with the core purpose and avoids fluff, though slightly long relative to the minimum needed.

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 complex tool with 17 parameters, no output schema, and significant prerequisites, the description covers the most important operational context: what happens after applying, financial safety, and refusal conditions. It does not mention the immediate return format or application ID, but the asynchronous human-review statement gives sufficient outcome context.

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. The description adds meaningful context for accept_terms (only after a human reads the sentence) and introduces the 100,000 ET10 holding requirement not present in the schema. It does not detail other parameters, but the schema already covers them thoroughly.

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 states the specific action ('apply to have a rebuilt app spun out as its own startup') with a specific verb and resource. It does not explicitly differentiate from siblings like bb_startup_line or bb_startup_bid, relying on the first sentence to convey the distinct purpose, which is clear enough but lacks explicit sibling contrast.

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 clear context for when to use the tool: when applying for a Build it Better spinoff, with explicit prerequisites (account holding at least 100,000 ET10, otherwise refused) and a specific instruction for accept_terms. It does not name alternative tools or exclusions, so it stops short of full when-not/alternatives guidance.

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