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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), but the description adds a genuinely useful behavioral fact not in the structured data: the code is returned even for unpublished Riddles, yet the embedded URL will not serve until publish. That caveat directly prevents a 'the embed is broken' misdiagnosis. It stops short of describing the returned markup (script vs iframe) or any rate/auth concerns.

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?

Two tight sentences, zero padding, with the identification and the key publish-state caveat both stated up front. Every clause carries information.

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For a single-parameter read with no output schema, the description covers the critical gotcha (unpublished Riddles) and the retrieval key. It leaves the shape of the returned code undocumented, though that is a minor gap for a string-returning lookup.

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% and the single UUID parameter is fully documented in the schema, so the description adds nothing beyond restating 'by its UUID'. Baseline 3 applies when the schema already does the work.

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 names a specific verb ('Gets') and a precise resource ('the HTML embed code for a Riddle'), which is materially narrower than riddle_get or riddle_preview. It never explicitly contrasts itself with those siblings, so an agent must infer that 'embed code' differs from previewing the Riddle.

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?

Usage is only implied by the resource name: an agent wanting markup to place on a page will pick this. There is no statement of when to prefer riddle_get or riddle_preview, and no prerequisites or exclusions are given.

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