mattermost_add_reaction

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

No annotations exist, and the description only states the action without disclosing behavioral traits like side effects (e.g., notifications), idempotency, or permission requirements. Insufficient for a mutation 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?

The description is a single sentence that efficiently conveys the core function without unnecessary words. Could be slightly improved with additional context but is appropriately concise.

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 tool has three required parameters, no output schema, and no annotations, the description is too minimal. It does not explain return values, confirmation, or constraints like duplicate reactions.

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 100%, so baseline is 3. The description adds no extra meaning beyond the schema, such as what 'emoji_name' format is expected or valid values.

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 uses the verb 'add' and specifies the resource 'reaction emoji to a message', clearly differentiating it from sibling tools like 'mattermost_post_message' which adds a text message.

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 is provided on when to use this tool versus alternatives, such as when to add a reaction versus posting a reply. Lacks any when-not-to-use or prerequisite information.

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