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

Annotations already indicate a non-read-only but non-destructive, idempotent operation. The description adds useful behavior beyond that: it is the public front door, no invite code is required, an email is needed despite being optional in the schema, and the caller receives a spot number. This is meaningful additional context, especially with no output schema.

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?

Five short, direct sentences with no filler. The core purpose is front-loaded, followed by the key qualification and optional parameters. Every sentence contributes useful information.

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 waitlist signup tool with full schema coverage and idempotent annotation, the description covers the essentials: purpose, public access, required email, optional fields, and the returned spot number. It could more explicitly contrast with join/join_chain, but the 'No invite code needed' line largely addresses that.

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 schema already documents all four parameters. The description adds grouping by saying email is needed and want/platform are optional, which is helpful, but it does not add detail about the referral parameter beyond what the schema provides.

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 a human on the btw waitlist and get a spot number. Calling it 'The public front door' and noting 'No invite code needed' distinguishes it from invite-based sibling tools like join or join_chain.

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 gives clear context: this is the public entry point, no invite code is needed, and an email is required. It implies the tool is the right choice when a human does not have an invite code, but it does not explicitly name alternative tools or state 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.