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

Annotations already provide idempotentHint=true and readOnlyHint=false, but the description adds crucial context that this sends a 'real' Slack message through production, making the side effect explicit. It also restates idempotency in prose, reinforcing safe retry behavior. It does not disclose potential errors or rate limits, but the core behavior is well covered.

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 a single, front-loaded sentence that conveys purpose, timing, idempotency, and the production delivery path with no wasted words. Every element earns its place.

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 only two well-documented parameters and no output schema, the description is nearly complete: it says what happens, when to call it, and that it is idempotent. It could have explicitly mentioned preview alternatives or side-effect prerequisites, but the current content is sufficient for an agent to select and invoke correctly.

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% and parameter descriptions ('Setup-session ID', 'Secret returned at creation') are clear. The tool description itself does not add parameter-specific meaning, so the baseline score of 3 is appropriate because the schema already carries the semantic weight.

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 verb 'send' and resource 'real Slack setup message through the production delivery path,' distinguishing it from preview-like siblings. It also includes a key sequencing cue ('After route application') that adds specific scope.

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 phrase 'After route application' indicates when this tool should be used, and 'real Slack setup message through the production delivery path' implies it is for actual delivery rather than preview. However, it does not explicitly name alternatives like preview_review_router_setup or state when not to use it.

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