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

The description adds the key behavioral detail that the operation overwrites the current value, which is not fully captured by annotations alone. It also recommends a read-before-write pattern, giving useful context beyond the idempotentHint and destructiveHint annotations. No contradiction with annotations.

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 structured with sections, but it repeats the opening sentence almost verbatim in the 'When to use' section and includes redundant markdown formatting. It could be condensed to two or three sentences without losing key guidance.

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 mutation tool with three fully-documented parameters and no output schema, the description covers essential context: overwrite semantics, required pre-calls, and parameter validation. It does not describe return values, but this is a minor gap given the lack of an output schema.

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 input schema already provides complete descriptions for all three parameters (100% coverage), so the description adds little new parameter-level information. It repeats the bonus_entries range and requiredness, and the pre-call validation advice is helpful but not essential for schema clarity.

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 that the tool updates the bonus entries value for a participant in a sweepstakes, using a specific verb and resource. It precisely identifies the target field, distinguishing it from other update tools focused on different resources.

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 provides explicit pre-call guidance: use get_participant first to check current bonus entries, and fetch_sweepstakes if the user provided a sweepstakes name instead of a token. While it does not explicitly mention alternative tools to avoid, the context for correct use is clear.

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