add_reaction

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

Annotations indicate a non-read, non-destructive write operation. The description confirms adding a reaction but adds no new behavioral details (e.g., side effects, permissions, or response). With annotations providing the core safety profile, the description's contribution is minimal.

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 sentences, no wasted words. The first sentence states the core purpose, the second provides a crucial usage hint. Efficient and well-structured.

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?

Given the presence of an output schema (not shown but noted), the description covers the essentials: what the tool does and how to find valid reaction types. It lacks mention of error cases or prerequisites, but for a simple tool it is reasonably complete.

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?

All three parameters (video_id, time, reaction_type) are fully described in the input schema with 100% coverage. The description repeats the hint from schema for reaction_type but adds no new meaning beyond that.

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 'Add an emoji reaction to a Loom video at a specific timestamp' with a specific verb and resource, and it distinguishes from sibling tools like 'add_comment_reaction' and 'delete_reaction'.

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 advises using 'get_frequent_reactions' to find valid reaction types, providing helpful guidance. However, it does not specify when not to use the tool or compare with similar tools like delete_reaction.

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