add_reaction

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

With no annotations, the description discloses key behaviors: low-consequence write (non-destructive), idempotent behavior, and no draft/confirm. This is sufficient for a reaction tool.

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 filler. Critical information is front-loaded. Excellent conciseness.

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 reaction tool, the description covers key behaviors and one parameter. However, missing parameter details for channel/ts and workspace (optional) could lead to incorrect invocation. Output schema exists but not shown.

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 coverage is 0%, so description must explain parameters. Only emoji is explained (colon-stripped name). channel and ts receive no explanation, and workspace is omitted. This leaves ambiguity.

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 explicitly states the action (add) and resource (emoji reaction to a message). It clearly distinguishes from sibling tools like send_message or send_reply_quote by focusing on reactions.

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?

Provides usage context: explains the emoji format, notes low-consequence write without draft+confirm, and mentions idempotency with soft success on duplicates. Does not explicitly state when not to use, but the guidance is clear enough.

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