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

With no annotations, the description carries the full burden and does so well: it discloses the server never sees a pass, the unlinkability conditions (pinning the mint key, Tor vs direct lane), the one-per-day-per-caller limit, and that it never sees an unblinded pass. Auth requirements are only implied by 'per caller,' which keeps it from a 5.

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 purpose is front-loaded, but the middle sentence is a dense run-on packing unlinkability, witness-chain, and Tor caveats into parentheticals full of insider jargon (K3, mint key, direct lane). It is mostly one paragraph and could be organized so the operational instruction (unblind locally) is not buried at the end.

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 complex crypto tool with no annotations and no output schema, the description covers purpose, privacy behavior, rate limits, and the unblinding step, which is enough for an agent to invoke it correctly. It leaves some ambiguity about caller identity/auth, but the core is complete.

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 0%, so the description must compensate, and it does: it states the tokens are up to 20, BLINDED, base64-encoded, and sourced from plus-sdk blindTokens(). That adds real semantics beyond the bare array-of-string schema, though it doesn't restate the min/max item bounds.

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 action chain: submit up to 20 blinded tokens and receive blind signatures, framed as 'Try Plus before paying.' It contrasts with the paid path ('identical BLINDED passes to paid ones') so the agent can distinguish it from the paid claim flow, though it never names the sibling (robyn_plus_claim) explicitly.

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?

Clear usage context: use this to try Plus before paying, with the constraint 'One trial per day per caller.' It tells the agent when the tool is appropriate but stops short of explicitly naming the alternative to use once the trial is exhausted or the paid path to prefer.

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