slack_post_message

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

No annotations are provided, so the description carries the full behavioral burden. It discloses that messages support Slack markdown, but it omits important write-operation context such as required permissions, whether the bot must already be in the channel, rate limits, or error behavior.

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 short, front-loaded with the core action, and then structured into parameter notes. Every sentence adds relevant information without unnecessary filler.

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 simple two-parameter write tool, the description covers the basic action and parameter semantics, and the output schema means return values need not be explained. However, it remains incomplete on operational prerequisites such as authentication and channel membership, which are relevant for a Slack post 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 0%, so the description must compensate, and it meaningfully explains both required parameters. It states that channel can be a name without '#' or a channel ID, and that text supports Slack markdown, which adds real meaning beyond the bare schema.

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 states a specific verb and resource: 'Send a message to a Slack channel.' This clearly distinguishes it from the list and read siblings, and an agent can understand the basic action without opening the schema.

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 purpose implies the use case, but the description gives no explicit when-to-use, when-not-to-use, or alternative guidance. It does not mention when to use slack_read_channel or slack_list_channels instead, leaving routing to the agent.

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