list_downloads

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

The description adds meaningful behavioral context beyond the readOnlyHint annotation: downloads are 'tracked since startup' (not historical), and the output includes status and saved file path. Since annotations already establish read-only safety, the description needs only to add scope and output details, which it does effectively.

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, tightly worded sentence: 'List downloads tracked since startup, including status and saved file path.' No wasted words. Every part contributes essential information, making it highly concise and well-structured.

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?

The tool has no output schema, so the description must clarify return values; it does so by mentioning status and saved file path. It also defines scope ('since startup'). With four optional parameters already documented in the schema, this is adequately complete. A small gap is that ordering or pagination behavior is not mentioned, but this is minor for a list tool.

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 parameters (limit, format, status, urlContains) are already fully documented. The description does not add additional semantic meaning about parameters; it only mentions output fields. Since the schema carries the parameter burden, the baseline score of 3 is appropriate.

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 is specific and clear: 'List downloads tracked since startup, including status and saved file path.' It uses a strong verb ('list'), names the resource ('downloads'), and adds scope ('since startup') and key output details. This clearly distinguishes it from sibling tools like clear_downloads, which is a mutation, and navigate_page, which has a different resource.

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 implies usage by stating it lists downloads, which is obviously the intended use. There are no explicit exclusions or alternatives, but there are no direct alternatives for listing downloads among the siblings. The context is clear enough for an agent to know when to invoke this tool.

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