firefox_downloads

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

Annotations already declare destructiveHint=true, readOnlyHint=false and openWorldHint=true, so the risk profile is supplied structurally. The description adds useful scope ('this extension', 'current session') but does not warn that cancel is irreversible, what happens to a paused download across sessions, or that operations target a single downloadId — context that would matter for a destructive tool.

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?

A single, front-loaded sentence with no filler or redundancy. It is efficient, though its brevity comes at the cost of the parameter guidance noted elsewhere.

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 two-parameter, destructive, no-output-schema tool the description covers domain scope but omits the action semantics and the downloadId conditional. An agent could invoke it, but only by inferring behavior from the enum rather than from prose.

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 0% and the description mentions neither parameter. The action enum (list/pause/resume/cancel) and the conditional requirement of downloadId for all but 'list' go entirely undiscussed, leaving the description to add nothing beyond the raw schema.

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?

States a specific verb pair (list/manage) and resource (downloads), and narrows scope to downloads 'initiated by this extension in the current session', which distinguishes it from the sibling firefox_download that starts downloads. It never names a sibling explicitly, but the domain boundary is inferable.

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?

Coverage of when to call it is only implied by the word 'manage' — there is no explicit guidance on which action to pick, nor any statement that downloadId is required for pause/resume/cancel but not for list. An agent must read the enum to discover that.

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