messages_reply

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

Annotations already declare destructiveHint=true and openWorldHint=true, so the bar is lower. The description still adds real context: the message reaches other people externally and the agent should state the effect and obtain user confirmation first. That is genuine behavioral guidance beyond the structured hints, though the 'deletes, or redirects data' clause is boilerplate.

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?

Front-loaded with the purpose, followed by the safety warning and technical endpoint references. No wasted sentences, though the transport metadata parenthetical (POST/gRPC/socket) is of marginal use to an agent selecting the tool.

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?

This is a complex mutation with a large nested payload, no output schema, and no parameter documentation. The description does not help an agent construct the content object or understand the enum values, so it is materially incomplete for a tool of this complexity.

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 0% for four required parameters, including a deeply nested content object with a 20-value type enum, attachments, interactive blocks, and presentation options. The only nod to parameters is 'quoting it', which loosely maps to messageId, but nothing explains chatId, channelId, or the content type codes.

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 ('Reply to a message, quoting it'), which is enough to tell it apart from messages_send at a glance. It does not explicitly name any sibling, so it falls short of a 5.

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?

There is no statement of when to choose reply over messages_send, messages_forward, or messages_react, nor any prerequisites. The confirmation instruction is a safety step, not usage routing.

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