tg_react

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

Annotations already mark the tool as mutating, idempotent, and non-destructive; the description adds real behavioral context on top of that: omitting `emoji` removes the reaction, and unsupported emoji/list attempts are refused before chat lookup. No contradiction with the annotations is present.

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 compact and front-loaded: the core action and removal behavior come first, followed by a separate, focused caveat about Premium. Every sentence earns its place and there is no filler or restatement of the schema.

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 4-parameter mutation tool with no output schema, the description covers the primary action and the most important `emoji` edge cases, while annotations cover idempotency and safety. Still, it omits `big` semantics, chat/message_id format expectations, and return/error behavior beyond the Premium refusal, leaving small but real gaps.

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?

With 0% schema description coverage, the description supplies useful meaning for `emoji`: optional, removal on omission, custom-emoji IDs/lists require Premium, and exactly one plain emoji otherwise. However, `big` is left unexplained and the exact input format for a 'list of several reactions' is not defined, so it does not fully compensate for the missing schema descriptions.

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 first sentence states a specific verb ('React'), a specific resource ('a message'), and the mechanism ('with an emoji'), and immediately clarifies the alternative mode of removing a reaction by omitting `emoji`. This makes the tool's purpose unmistakable and distinguishes it from siblings like tg_send, tg_send_sticker, and tg_pin_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?

It explicitly describes two usage modes: adding a reaction and removing one by omitting `emoji`. It also gives a clear constraint about when calls are refused, namely custom-emoji IDs or multiple reactions without a Premium subscription. However, it does not name sibling tools or provide when-not-to-use guidance, so it falls short of full routing.

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