Send message

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

The annotations only indicate readOnlyHint=false and destructiveHint=false, so the description carries part of the transparency burden. It adds useful context about mentions being suppressed by default and dry_run support, but does not disclose other behaviors such as permission requirements, rate limits, or response format. This is adequate but has gaps, warranting a 3.

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 concise at three sentences. The first sentence states the primary action and optional features, the second efficiently lists alternatives, and the third provides a key behavioral warning about mentions. Every sentence earns its place with 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?

The description covers the tool's core purpose, key alternatives, and important behavioral details (mentions, dry_run). Given 8 parameters and no output schema, it provides enough context for an agent to select and invoke the tool correctly, though it could mention what the response contains or error conditions, but those are not essential for a send operation.

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 100%, so the schema already documents all parameters well. The description adds only marginal value by restating mentions default and dry_run, which the schema also covers ('Which mention types may ping. Default none.' and 'Preview without sending.'). Since the schema carries the heavy lifting, baseline 3 is appropriate.

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 clearly states the tool's function: 'Send a message to a channel, optionally as a reply or with embeds.' It uses a specific verb (send) with a clear resource (message to a channel) and distinguishes from sibling tools by naming send_dm, send_webhook_message, and schedule_message as alternatives for different use cases.

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 provides explicit usage guidance by naming alternatives: 'For a private message to one person use send_dm; to post under a custom name and avatar use send_webhook_message; to send later use schedule_message.' It also notes the default behavior for mentions and the existence of dry_run, giving clear context for when to use this tool.

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