install_extension

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

Annotations already indicate the tool is not read-only (readOnlyHint=false), which aligns with the install action. However, the description adds no further behavioral context, such as side effects, required permissions, failure modes, or whether installation modifies browser state permanently.

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 two sentences, front-loaded with the primary action, and every phrase adds value. No redundancy or fluff.

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 should ideally mention the return value (e.g., extension ID) or error behavior. It does not, but it covers the core functionality adequately. Slightly incomplete for a mutation 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 provides 100% parameter descriptions, and the description adds context: it explains the three 'type' options (archivePath, base64, path) with file extensions and clarifies the 'permanent' parameter as Firefox-specific requiring signed extensions. This complements the schema effectively.

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 action (install), the resource (Firefox extension), and the method (WebDriver BiDi webExtension.install). It also lists supported sources (archive, base64, unpacked), making the tool's purpose distinct from siblings like uninstall_extension.

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 when to use (for installing extensions) but lacks explicit guidance on when not to use or prerequisites (e.g., Firefox must support BiDi, signed vs. temporary). No mention of alternatives among siblings.

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