Complete giveaway

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

Annotations already declare the safety profile (not read-only, idempotent, non-destructive, open-world). The description adds one behavioral premise (a prerequisite settled-winner state), which is genuine added context, but it says nothing about whether completing is reversible, what happens to entrants/prizes, or any auth requirements.

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?

A single eight-word sentence that front-loads the action and adds a precondition; no filler or redundancy. Appropriately sized for a simple state-change tool.

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 two-parameter idempotent mutation with no output schema and rich annotations, this is close to adequate. But the unresolved overlap with giveaways_close and the absence of any note on reversibility or side effects leave a meaningful gap for an agent choosing and calling the tool.

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% for both parameters (channel, giveawayId) including format and default resolution details, so the schema carries the semantic load. The description adds nothing about parameters, which is the expected baseline when coverage is complete.

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?

States a specific verb+resource ('Mark a giveaway as complete'), which is clear on its own. However, it does not differentiate from the sibling giveaways_close, which an agent could easily confuse with 'complete', so it falls short of full sibling discrimination.

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 phrase 'once winners are settled' gives an implied precondition for when to invoke it, which is useful. But there is no explicit when-not guidance and no reference to alternatives such as giveaways_close, giveaways_reopen, or giveaways_refund, leaving selection between these similar tools to inference.

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