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

Annotations already declare readOnly/idempotent/openWorld/non-destructive, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: it is a full working router (not a partial or shadow path), it falls back to nothing rather than a degraded service, and its results are compared against the stable router to drive merges.

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?

Front-loaded with the key framing, but it is repetitive: 'identical... same arguments, same response shape' and 'Falls back to nothing — this IS a full working router, just the experimental edge' restate the same point twice. The retirement date of the last candidate is borderline trivia that dilutes the signal.

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?

No output schema exists, so the description compensates by stating the response shape matches ask_pipeworx and that unknown pack slugs surface in _meta.pack_scope. That is sufficient for an agent to call the tool correctly; only the absence of any concrete response fields keeps it short of 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 coverage is 100% and each parameter (including the alias set and the packs scoping behavior with its full-catalog fallback) is fully documented inline. The description only says the arguments are identical to ask_pipeworx, which adds a little cross-reference value but nothing the schema does not already carry. Baseline 3 applies.

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+resource ('universal router' that answers a natural-language question) and explicitly frames itself as the beta twin of ask_pipeworx with the same 6,821 tools, arguments, and response shape. The agent can distinguish it from ask_pipeworx and ask_pipeworx_grounded from the description alone.

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 a clear use condition: 'Use it exactly like ask_pipeworx when you want the newest routing.' It also candidly notes no candidate is currently active, which effectively tells the agent there is no routing advantage right now. It lacks an explicit 'use X instead when...' routing rule, but the context is unambiguous.

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