Add a comment reaction

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

Annotations already indicate readOnlyHint=false and openWorldHint=true. The description adds the HTTP method and endpoint, aligning as a mutation, but it doesn't disclose potential side effects, idempotency, or duplicate handling beyond the basic POST behavior.

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 that states the HTTP method, endpoint, and key emoji example. Every component is necessary and structured efficiently, leaving no waste.

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 tool with three required parameters and no output schema, the description plus schema give enough information to make a basic call. But it omits any context on the reaction-add behavior, such as whether existing reactions are updated or special validation, leaving the agent without complete picture of the mutation outcome.

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 covers the file and emoji parameters with descriptions, and the tool description reinforces the emoji shortcode format with the path. However, comment_id remains undocumented in the schema and the description only mentions it in the URL, offering no additional meaning beyond the parameter name.

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 title 'Add a comment reaction' and the description's POST endpoint clearly identify a specific verb and resource. However, it does not explicitly contrast with sibling reaction tools such as get_comment_reactions or delete_comment_reaction, so it lacks sharp sibling differentiation.

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 does not state when to use this tool versus the related reaction tools. An agent gets no explicit cue that this should be used to create a reaction, while get_comment_reactions retrieves and delete_comment_reaction removes them, so the intended context must be inferred.

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