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

Annotations already cover read-only/idempotent/non-destructive safety, so the bar is lower, yet the description still adds rich behavioral context: candidate improvements are 'enabled live whenever one is under test,' the current state matches ask_pipeworx exactly because the last candidate retired, and results feed merge decisions. The 'falls back to nothing — this IS a full working router' clause preempts a likely misconception about beta tools.

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?

Three dense sentences, each earning its place: identity/beta behavior, current state and usage, and no-fallback reassurance. Slightly long and the parenthetical retirement date plus the 'falls back to nothing —' phrasing is a touch awkward, but information density justifies the length.

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 conceptually simple question-routing tool wrapped in experimental meta-info, the description answers the key uncertainties: what differs from stable, whether it's reliable right now, when to prefer it, and that the response shape matches ask_pipeworx. It leans on ask_pipeworx for deep behavioral detail rather than describing the router's function independently, and no output schema exists, so a bit of direct response-format context would have pushed this to a 5.

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 the question parameter and all five aliases. The description only reinforces this with 'same arguments' as ask_pipeworx, which is a useful cross-reference but adds no new semantic meaning. Baseline 3 is appropriate since 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 and resource — 'identical universal router (same 5,798 tools, same arguments, same response shape)' — and distinguishes itself from the sibling ask_pipeworx by being the beta variant with candidate routing improvements. An agent can tell it apart from ask_pipeworx and ask_pipeworx_grounded 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?

Explicitly instructs when to use it: 'Use it exactly like ask_pipeworx when you want the newest routing.' It names the stable alternative, explains the comparison purpose, and clarifies that it is a fully functional router with no fallback — closing the obvious question of whether the beta should be treated as a stub.

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