install_extension

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

The annotation readOnlyHint=false already indicates a mutating operation, so the description is not required to restate that. It does add the WebDriver BiDi command and source type support, but it does not disclose side effects such as the temporary-by-default nature of the install or requirements like signed extensions for permanent installs. These are partially covered in the schema, so the description adds moderate value beyond annotations.

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 concise, consisting of two sentences that front-load the primary purpose and then list the supported input formats. There is no fluff or redundancy, making it highly efficient.

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 full parameter schema and no output schema, the description sufficiently conveys the operation and options. It could be more complete by mentioning that installs are temporary by default or noting the permanent install requirement, but these details are in the schema. Overall, it is adequate but not exhaustive.

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 input schema provides 100% coverage with descriptions for all four parameters, including an enum for type. The description simply reiterates the three source types without adding new semantic details. Therefore, it meets the baseline but does not go beyond the 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?

The description clearly states the specific action (install) and resource (Firefox extension), mentions the underlying WebDriver BiDi command, and distinguishes itself from the sibling uninstall_extension. It also enumerates the three supported source types, leaving no ambiguity about its role.

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 makes clear when to use the tool (to install an extension) and the accepted source formats, but it does not explicitly state when not to use it or mention alternatives. The sibling context provides implicit guidance, but no explicit exclusions or comparisons are given.

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