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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the description need not restate that this is a write operation. The description adds no extra behavioral context beyond the act of adding a reaction, such as idempotency implications, limits, or side effects, but it is consistent with the annotations.

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 sentence that front-loads the action and resource, with no filler or redundant restatements. It is appropriately sized for the information it conveys.

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?

The description is too thin for a state-changing tool with no output schema Asi He. It does not describe what a successful response looks like, how reactions are represented (e.g., emoji vs. code), or any error conditions. The absence of reaction value guidance is a critical gap for an agent invoking this tool.

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?

The schema provides detailed descriptions for chat_id, message_id, and account_id, but the required reaction parameter has no schema description and the tool description does not specify valid values or format. With 75% schema coverage, the description fails to compensate for the completely undocumented reaction parameter, leaving the agent without guidance on what to pass.

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?

Description states a specific verb ('Add') and resource ('a specific LinkedIn message'), which distinguishes it from post and comment reaction tools. The provider and target are clear both in the description and the tool name.

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 names required parameters (chat_id, message_id) and how to obtain them ('normally discovered by reading the conversation'). However, it does not explicitly state when to choose this tool over related siblings like linkedin_react_to_post or message_add_reaction, nor does it mention exclusions or prerequisites beyond parameter discovery.

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