Slack List Reactions

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

Annotations already declare readOnlyHint=true, so safety is covered; the description adds nothing beyond that. It does not mention pagination behavior, what 'full' actually changes in the result, or how the default (authenticated user) is resolved, all of which would be useful context.

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 front-loaded sentence with zero filler. It is efficient, though the brevity comes at the cost of the guidance and behavioral detail noted above.

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?

With an output schema present, return values need no explanation, and the schema fully documents parameters. However, for a tool with pagination and a 'full' flag, the description should at least clarify scoping relative to slack_get_reactions, which it does not.

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%, so all four parameters are already documented in the schema, and the baseline is 3. The phrase 'made by a user' loosely maps to user_id but adds no semantics beyond what the schema states about defaults.

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 and resource: 'List reactions made by a user.' The 'made by a user' qualifier distinguishes it from the sibling slack_get_reactions, which presumably returns reactions on a message, though the description never names that sibling explicitly.

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?

No guidance on when to use this tool versus slack_get_reactions or other siblings, and no scenarios or prerequisites are given. The agent must infer the difference from the name alone.

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