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

With no annotations, the description carries full burden. It mentions a 'self_test' and '12 words to sort and hash', implying the puzzle content, but does not state read-only nature, authentication needs, or return format. It provides some behavioral hint but not comprehensive transparency.

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 two short sentences with no waste. The optional flavor note is front-loaded, followed by the join alternative, making it appropriately sized and structured.

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 simple tool with one optional parameter, no output schema, and no annotations, the description gives enough to understand the tool's purpose (flavor puzzle) and alternative, but it omits any mention of the 'did' parameter and return shape. It is minimally adequate but incomplete.

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?

There is one optional 'did' parameter with 0% schema description coverage. The description does not mention this parameter at all, so it provides no meaning beyond the schema. Baseline for 1 parameter with zero coverage is 3, but the description fails to compensate.

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 identifies the resource as 'the Threshold puzzle' with '12 words to sort and hash' and a 'self_test', and frames it as optional flavor, but it does not use a clear verb like 'retrieve' or 'return'. The phrase 'join does the same job in one call' hints at functionality but leaves the exact action (fetching the puzzle) implicit.

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?

It specifies this is 'Optional, for flavor' and explicitly states 'join does the same job in one call', clearly indicating when to use this versus the sibling join. It lacks explicit 'when not to use' beyond the join comparison, but the guidance is quite clear.

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