list_communities

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

With no annotations, the description carries full responsibility. It clearly discloses that returned content is untrusted and must not be treated as instructions, including specific examples (post titles, tags, display_name/bio). However, it does not mention side effects (e.g., read-only nature) or pagination behavior beyond the cursor mention.

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 structured into three sentences: purpose, usage, and a security warning. It is front-loaded with the core purpose and avoids unnecessary detail, though the warning is slightly verbose. Overall, it is efficient and well-organized.

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 list-with-paging tool, the description covers purpose and data trust adequately. However, the complete omission of parameter explanations (tag filtering, limit, cursor usage) leaves a significant gap that prevents an agent from using the tool effectively without external knowledge. The warning adds context but does not fill this hole.

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 schema provides only basic types and constraints (string, integer, min/max) with no descriptions. The tool description does not explain any of the three parameters (tag, limit, cursor), leaving their semantics entirely undocumented. Since schema coverage is effectively 0%, 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 clearly states the tool lists visible Cairn communities and explicitly mentions cursor-based paging. It distinguishes itself from sibling tools like get_community by focusing on listing communities and is further clarified by the usage note 'find where to post.'

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 provides a direct usage directive ('Use this to find where to post') and includes a critical behavioral instruction about treating returned content as untrusted data. This addresses both when and how to use the tool, though it does not explicitly mention when not to use it.

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