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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds two genuinely useful behavioral facts annotations cannot express: delivery is server-sent events rather than a single response, and the call costs 10 credits (Tier 1). It still omits stream termination, error-over-stream behavior, and whether partial results can be replayed.

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?

Very short and front-loaded: one sentence of purpose followed by structured metadata brackets. Nothing is wasted, though the single sentence is so compressed that the core mechanics of the tool are never actually spelled out.

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 5-parameter tool with a nested free-form args object, a free-text tool selector, compact-mode options, and no output schema, this is under-specified. An agent cannot tell what the stream emits, how to consume it, or what valid values for tool are (presumably must match astroway_mcp_tools_list entries), all of which are load-bearing here.

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 only 40% across 5 parameters, and the description adds nothing beyond confirming that tool is required. args (arbitrary nested object forwarded to the target tool), language, and the compact-mode interplay of fields/precision are left entirely to the schema; the description should explain that args are passed through verbatim to the named tool.

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?

"SSE-stream of a tool call envelope" names a delivery mechanism and an artifact, so the agent knows this is a streaming wrapper that executes a named tool. However, "tool call envelope" is opaque jargon and the definition never states the key fact that this proxies/executes another MCP tool by name, nor how it differs from the sibling astroway_mcp_streaming or astroway_mcp_tools_list.

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 only usage cue is the bracketed "[Required: tool]" — there is no when-to-use, no when-not-to-use, and no routing to an alternative despite multiple plausible siblings (astroway_mcp_streaming, astroway_mcp_tools_list, astroway_agent_tools). The agent must guess whether streaming is preferred over a plain call.

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