list_extensions

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

No annotations are present, so the description carries the burden. It discloses a useful non-obvious trait (works with no tabs open) and the exact output fields, confirming it is a non-mutating listing operation. It stops short of stating session-related behavior or error conditions, but for a simple list tool this covers the essentials.

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. Every clause ('List installed browser extensions', '(id, name, ...)', 'Works with no tabs open') adds distinct value.

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 simple enumeration tool with an output schema, the description covers the key purpose and a critical runtime precondition. The only missing contextual element is the meaning of session_id, which is already penalized under parameter semantics.

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 schema has 0% description coverage for the single parameter, and the description does not mention session_id at all. Since session_id is optional with a default, the gap is minor, but the description adds no meaning 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?

States a specific verb ('List') and resource ('installed browser extensions'), enumerating the returned fields (id, name, enabled, type, version). Clearly differentiated from siblings like set_extension_enabled and uninstall_extension by naming a read-only enumeration operation.

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?

Provides clear operational context ('Works with no tabs open') that tells the agent when it can be invoked. Does not explicitly name alternatives or exclusion conditions, but the purpose is unambiguous enough that the usage context is clear.

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