messages_send

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

Annotations already declare readOnlyHint=false, destructiveHint=true, and openWorldHint=true, so the safety profile is largely covered. The description usefully adds that the message reaches other people and that user confirmation should be obtained, but the phrase 'deletes, or redirects data' reads like generic boilerplate and is confusing for a send operation.

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 purpose is front-loaded, which is good, but the middle sentence is generic safety boilerplate that could apply to almost any tool, and the trailing transport-detail line (POST/gRPC/socket) adds little to selection. Trimmed to the first line plus addressing guidance it would be stronger.

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 a large nested payload schema, zero schema-description coverage, and no output schema, the description should explain at minimum how to target a recipient and what the content type enum encodes. Neither is addressed, and the distinction from specialized send siblings is absent, so it is not complete enough to call reliably.

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% across 6 parameters, including a deeply nested 'content' object. The description never explains addressing semantics — how channelId, chatId, contactId, username, and phoneNumber relate or when each is required — leaving the agent with no guidance beyond raw field names.

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 line gives a clear verb+resource (send a message) and even indicates the payload shape (a whole MessageContent). However, with siblings like messages_send_media, messages_send_poll, messages_send_location, and messages_send_interactive, it never states that this is the generic/full-payload sender versus the specialized ones, so the agent cannot confidently route between them.

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 when-to-use guidance and no mention of alternatives despite an unusually dense cluster of messages_send_* siblings. The only usage-adjacent text ('get the user's confirmation first') is a safety caution, not a selection rule for choosing this tool over messages_reply or the specialized send tools.

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