messages_send

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

Annotations already indicate a non-read-only, non-destructive operation. The description adds useful context: it's plain-text only, implies bot rate-limit behavior by recommending webhooks for high-volume, and states the return shape. It does not contradict annotations, though it could have noted permission requirements or side effects more explicitly.

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?

Well-structured with bolded sections, bullet points, an example, and return type. Every sentence serves a purpose, and the content is front-loaded with the most critical information. No fluff.

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?

Given the tool's simplicity (3 params, no nested objects, output schema present), the description covers purpose, usage, exclusions, example, and return values comprehensively. It's sufficient for an agent to invoke correctly without further guidance.

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?

Input schema covers 100% of parameters with descriptions, so the baseline is 3. The description adds a concrete example and return fields, but does not introduce additional semantic meaning beyond the schema's parameter docs.

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 description opens with a specific verb+resource: 'Send a plain-text message to a Discord channel.' It clearly distinguishes this tool from rich-layout senders (components_v2_send) and webhooks_execute, and the scope (plain-text, programmatic announcements) is explicit.

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?

Provides explicit 'When to use' and 'When NOT to use' sections, naming alternative tools (components_v2_send, webhooks_execute) and a concrete user-request example. This fully guides the agent on selecting this tool over siblings.

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