browser_set_storage

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It simply says 'Write' without explaining that it overwrites existing keys, that sessionStorage is cleared when the tab closes, or that the value must be a string. It also does not disclose potential side effects or whether the page must be loaded.

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 that immediately states the tool's function without any filler or redundancy. It is appropriately sized for a simple operation and front-loaded with the key information.

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 mutation tool with no annotations and no output schema, the description is too sparse. It omits important context like overwrite behavior, storage lifetime nuances, and any conditions that could cause the write to fail. This is a significant gap when the agent needs to understand the consequences of setting storage.

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 covers all three parameters with descriptions such as 'Key', 'Storage type', and 'Value', giving 100% coverage. The description does not add any meaning beyond the schema, such as clarifying value constraints or the relationship between type and storage behavior, so the baseline score of 3 applies.

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 'Write to localStorage or sessionStorage' clearly specifies a verb (Write) and a resource (browser storage types), making the tool's purpose immediately obvious. It also distinguishes from the sibling tool browser_get_storage, which likely reads storage, and from cookie-related tools.

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 that this tool is used to write to browser storage, but it does not explicitly state when to use it instead of alternatives like browser_get_storage or browser_execute_js. No exclusions, prerequisites, or recommended contexts are mentioned, so guidance is only implicit.

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