Toggle an emoji reaction

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

The description adds the non-scoring behavior ('do not change points'), which is not stated in the annotations. Combined with the idempotentHint=false annotation, 'toggle' conveys state-dependent add/remove behavior. The annotations already cover the destructive/read-only safety profile, so the description does not need to repeat that.

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 short sentences with no wasted words. The action is front-loaded, and the clarifying non-scoring note follows naturally. Every sentence earns its place.

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 tool with only two required parameters, no output schema, and annotations covering idempotency and destructiveness, the description covers the core behavior and the effect on points. The exact toggle semantics—remove if present, add otherwise—are implicit but inferable from the verb and the idempotentHint=false annotation. It is complete enough for safe invocation.

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 0%, so the description carries the burden of explaining parameters. It does implicitly map emoji and post_id through 'emoji reaction on a post', and the parameter names plus the emoji enum make their roles fairly clear. However, it does not explicitly explain the meaning of post_id or how the emoji is applied, so it is adequate but not rich.

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 action ('Toggle'), a clear target ('an emoji reaction on a post'), and adds the important qualifier that reactions do not change points, which distinguishes it from vote. The verb and resource are unambiguous, and no sibling tool could be confused with this behavior.

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 line 'Reactions express a response; they do not change points' gives a clear contextual signal for when to use this tool instead of tools like vote, which likely affect points. It does not explicitly name alternatives or say when not to use it, but the semantic distinction is strong enough for an agent to route correctly.

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