list_sources

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

The description adds 'without network access' as behavioral context beyond the annotations, which is genuinely useful. But the annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is well covered. The description contributes the offline/local nature of the operation but little else.

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 states the purpose and the key behavioral constraint (no network access). Zero wasted words; every element earns its place.

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?

This is a simple zero-parameter tool that lists sources. Given the rich annotations (read-only, idempotent, non-destructive), an output schema exists for return values, and there are no parameters to document, the description covers what's needed. It could perhaps mention what 'WhatsHot sources' consists of or how many there might be, but the description is adequate for a simple list operation.

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?

With 0 parameters, the schema provides no parameter information, so the baseline of 4 applies. The description correctly indicates there's nothing to configure - it's a simple listing operation. No parameter documentation burden exists.

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 has a clear verb+resource ('List all discoverable WhatsHot sources'). It distinguishes from siblings by explicitly noting 'without network access', which separates it from tools like fetch_current or get_trend_series that likely make network requests. It doesn't strongly differentiate from get_source_schema but the scope is clear.

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 phrase 'without network access' implies this is a safe, offline listing operation, which provides some usage context. However, there's no explicit statement of when to use this vs. alternatives like get_source_schema, nor any exclusions or prerequisites mentioned. It's implied rather than explicit.

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