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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds non-obvious behavioral context: results are grouped by category rather than returned as a flat 'items' list, and the build configuration is deliberately omitted. It does not discuss pagination or limits, hence not 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?

Front-loaded with the core purpose in the first clause, and every remaining sentence carries information (grouping behavior, return shape, alternatives). It is a dense, somewhat run-on single paragraph with nested quoting, which costs it a point on readability, but little is wasted.

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?

With no output schema, the description compensates by spelling out the return shape ({categories: {<category>: [{id, title, type, blocksCount, image, icon, createdAt, riddle, isPublic}]}, total}) and the key structural quirk (grouped, not flat). Combined with sibling routing, an agent has everything needed to call and interpret it.

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 both parameters in detail (the exact Riddle types, the snake_case category slug). The description only notes that 'category' and 'type' narrow the results and that omitting category reveals existing ones, which largely duplicates the schema. Baseline 3 is correct.

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 (lists public templates) and immediately differentiates from the sibling riddle_template_list ('as opposed to riddle_template_list's own ones'). It also clarifies what this tool does NOT include (build configuration) versus riddle_template_get. An agent can distinguish it from siblings 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 states that calling with no arguments is how you discover the available categories, and names the alternatives: riddle_template_get for the build configuration, or handing the id to riddle_template_use. Both when-to-use and routing to alternatives are present.

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