Set localStorage item

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

The description discloses that the tool writes, aligning with readOnlyHint=false, but it does not mention potential overwriting of existing keys or persistence behavior; annotations provide minimal additional side-effect detail.

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 concise sentence with no redundant information, front-loading the action and resource.

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 two-parameter setter with no output schema, the description is adequate, though it omits minor context such as overwrite semantics or return value.

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 already fully describes both parameters (key and value), and the description adds no extra meaning beyond what is in the parameter descriptions.

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 ('Write') and the resource ('one localStorage key'), which distinguishes it from sibling tools like browser_localstorage_get, browser_localstorage_delete, and browser_localstorage_clear.

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 for storing a value in localStorage, but it does not explicitly state when to choose it over related get/delete/clear tools or mention any context.

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