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

Although annotations already declare idempotentHint=true and destructiveHint=false, the description adds meaningful beyond that: it creates a waitlist entry, requires no key, and returns a specific JSON shape. This enriches the behavioral profile without repeating annotation data or contradicting it.

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?

Three sentences: (1) purpose and core inputs, (2) when and when-not with alternatives, (3) return format and side effect. Every sentence earns its place, the purpose is front-loaded, and there is zero filler.

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 write tool with only 4 parameters, an output schema absent, and high schema coverage, this is complete. It covers purpose, usage guidance, behavioral side effects, auth requirements, and return shape. There are no obvious gaps for an agent to call it correctly.

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 only paraphrases the qualifier values already in the schema and does not add meaning to optional parameters like source or product_updates. It works, but adds no real semantic value over the JSON schema.

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 opens with a specific verb and resource: 'Join the FlexYield early-access waitlist with an email and a qualifier'. It clearly defines the qualifier values and immediately contrasts the tool with siblings like get_key, manage_tickets, and join_enterprise_wishlist, making the purpose unmistakable.

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?

It explicitly states when to use the tool ('only when a human asked to be kept informed') and names the exact alternatives for other scenarios (get_key for agent access, manage_tickets for support, join_enterprise_wishlist for enterprise). This is textbook usage guidance with conditions and exclusions.

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