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

Annotations already declare openWorldHint=true, idempotentHint=false, destructiveHint=false, so the safety profile is covered. The description adds real behavioral detail beyond that: the exact message payload, the extra JSON content (steps, links, Mermaid code) sent to webhooks, and the rule for choosing the public vs private link. It does not mention failure modes or that repeat calls produce duplicate posts.

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?

Four sentences, each earning its place: destination list first, payload second, webhook variant third, link rule and parameter sourcing last. No filler and the most important information is front-loaded.

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 side-effecting post tool with no output schema, the description covers what is sent and where, and how to obtain the channel_id. It omits error/rejection behavior (invalid webhook, channel not found) and any permission requirements, which would round it out.

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 all three parameters are already documented. The description reinforces channel_id's source and explains what the default summary contains (which summary_lines overrides), but adds no syntax or format detail the schema lacks. Baseline 3 applies when the schema does the heavy lifting.

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 (Post) and resource (flow) plus the exact set of destinations: Slack, Microsoft Teams, Google Chat, Discord, or webhook. This cleanly separates it from siblings like send_flow_to_confluence, send_flow_to_jira, send_flow_to_notion, and share_flow without opening any 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?

Gives concrete operational context: 'Get the channel_id from list_channels', tying the required parameter to the sibling tool that produces it. It does not explicitly state when to prefer this over the other send_flow_to_* siblings, so it stops short of full when/when-not guidance.

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