List prompt categories

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

Annotations already declare readOnlyHint=true, covering the safety profile. The description adds that the tool returns counts of prompts per category, which is useful context about the output. However, it does not describe any edge cases, pagination, or further behavioral details, which would be nice given there is no output schema.

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 a single sentence that front-loads the core function and appends a practical use case. Every word earns its place; no fluff or repetition.

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 no parameters and no output schema, the description adequately conveys what it returns (categories with prompt counts) and why it's useful. It doesn't specify the exact data structure, but for a category listing that is acceptable. The sibling context is also implicitly covered through the use-case note.

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?

The tool has zero parameters, and the schema is empty with 100% coverage. Per the rubric, a baseline of 4 applies for 0 params, and the description doesn't need to add parameter details. Nothing is missing here.

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 clearly states the tool's verb ('List') and resource ('the user's prompt categories'), plus the key detail that it includes counts of prompts per category. This distinguishes it from sibling tools list_prompts and get_prompt, which deal with prompts directly.

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?

The description explicitly mentions a use case: narrowing list_prompts on a large library. This gives clear context for when to use the tool, though it does not explicitly state when not to use it or directly name alternatives. Still, the tie to list_prompts implies the distinction.

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