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

With no annotations, the description carries the full burden. It explains the behavior: it places the founder on a waitlist, is free for now, sends one email without spam, and allows unsubscribe. It also discloses the 'confirmed' flag as a required attestation. It is transparent about being a non-destructive, consent-based action even though no annotations are provided.

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 concise and front-loaded with the main action. It lists the items and the condition. The only slight issue is the parenthetical enumeration which, while informative, adds a bit of length. However, it remains efficient and every sentence contributes to clarifying usage.

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 tool with 3 parameters, all documented, and no output schema, the description covers the essential aspects: what it does, when to call, and the consent requirement. It does not specify the return value, but since there is no output schema and the action is a simple side effect, it is sufficiently complete. Minor gaps: it doesn't mention what happens if the email is invalid, but that is likely handled elsewhere.

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 already provides 100% coverage with descriptions for each parameter. The tool description references the email and confirmed parameters but adds little beyond the schema. It mentions the 'product_url' indirectly ('product'), but the schema already covers it. Thus, the description adds marginal value, but since schema coverage is full, a baseline of 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 clearly states the action ('Put the founder on the waitlist'), the target (marketinque project), and lists the specific items involved. It also distinguishes itself from siblings by emphasizing the waitlist and email confirmation, which is unique among the sibling tools that are mostly 'get' operations.

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 explicitly states the precondition: 'Call ONLY after the founder gave you their email and said yes in this session.' It also implies not to use it otherwise and mentions the confirmation flag 'confirmed' as an attestation, which provides clear guidance on when and how to use the tool.

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