Post to giveaway

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

Annotations cover the safety profile (write, non-idempotent, non-destructive, open-world), and the description adds meaningful context beyond them: the request body format is undocumented and the id semantics are ambiguous. Disclosing that the body format is undocumented is genuinely useful for invocation planning.

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?

Two tight sentences with the endpoint front-loaded and the alternative recommendation at the end. Minor density from the HTTP-path prefix, but nothing wasted.

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 mutation tool with no output schema and a nested free-form object body, the description honestly flags the undocumented body but doesn't describe the effect on the giveaway or any prerequisites beyond the token default already in the schema. Adequate but leaves resolution of the core ambiguity to the agent.

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 description coverage is 100%, so the schema already documents channel defaulting, giveaway fields, and the 24-hex giveawayId pattern. The prose adds no parameter detail beyond what the schema provides, so the baseline 3 applies.

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 gives the concrete endpoint (POST /giveaways/{channel}/{giveawayId}) and explicitly distinguishes this tool from the sibling giveaways_create. However, the actual function is hedged: it relays StreamElements' label 'Create a new Giveaway' while noting the id 'may refer to the ongoing giveaway,' so what the tool truly does remains muddled.

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 names an alternative with a condition ('Prefer giveaways_create to create one'), which is clear negative guidance, but never states the positive case for choosing this tool. An agent is left guessing when giveaways_create_by_id is actually the right call.

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