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

No annotations are provided, so the description carries full burden. It discloses that the tool is free, no payment, and describes the phase-based funnel. However, it does not detail side effects or state persistence, which is acceptable given its interactive nature.

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 two sentences, front-loaded with critical usage instruction ('START HERE'), and concisely explains the funnel and exit condition without extraneous words.

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?

Given the complexity of a stateful funnel tool, the description provides enough context for an agent to invoke it correctly: the order of phases, the free nature, and the escape hatch. It does not elaborate on each phase's response, but the agent likely understands its own flow.

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 low (33%), but the description adds value by explaining the interest parameter ('pass interest:false to bow out') and the symbol parameter's role in the sample phase and its relation to evaluate_symbol. The phase enum is listed but not detailed; the flow description compensates partially.

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 explicitly states the tool's role as the entry point and subscription funnel for the agent, with a clear verb+resource ('pitch' as intro). It distinguishes itself from siblings by noting that other tools like evaluate_symbol are paid and used for other purposes.

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 clearly states 'your first call to this agent MUST be pitch' and provides explicit guidance on when to use it and how to exit (interest:false). It also mentions that for non-sample symbols, evaluate_symbol should be used, offering an alternative.

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