list_supported_providers

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

No annotations are provided, so the description carries full burden. It states what the tool does (lists providers) but doesn't disclose behavioral traits like whether this is a read-only operation, if it requires authentication, what format the output takes, or if there are rate limits. For a tool with zero annotation coverage, this is a significant gap in behavioral context.

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, efficient sentence in Chinese that directly states the tool's purpose with zero wasted words. It's appropriately sized for a simple listing tool and front-loads the core functionality immediately.

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?

Given the tool's simplicity (0 parameters, no output schema), the description is minimally adequate. It states the purpose but lacks context about output format, authentication needs, or when to use it relative to siblings. For a tool with no annotations and no output schema, the description should ideally provide more behavioral guidance to compensate.

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 0 parameters with 100% schema description coverage, so the schema already fully documents the input (none required). The description doesn't need to add parameter information, and it doesn't contradict the schema. A baseline of 4 is appropriate for zero-parameter tools where the schema handles all input documentation.

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 '列出支持的邮箱提供商' (List supported email providers) clearly states the verb (list) and resource (email providers). It distinguishes from siblings like configure_email_server or send_email by focusing on provider enumeration rather than configuration or sending operations. However, it doesn't explicitly differentiate from setup_email_account or test_email_connection which might involve providers.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., whether this should be called before setup_email_account), exclusions, or relationships to sibling tools like configure_email_server or setup_email_account. The agent must infer usage from the tool name alone.

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