browser_screenshot

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

Annotations are all false, so the description bears full burden for behavioral transparency. It states the tool saves a screenshot (implying a write operation) and returns a path, but it does not disclose potential side effects (e.g., file overwrite, permissions, storage location) or any constraints on usage. This lack of detail limits transparency.

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 extremely concise, consisting of two sentences that are front-loaded with essential information. Every word serves a purpose, with no redundancy or filler. This is a model of efficiency.

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 tool's simplicity (no parameters, no output schema), the description provides adequate context: it describes the action and the return value. However, it does not explain what 'BC' stands for or the format of the returned path, which could be useful for an agent. For a low-complexity tool, this is nearly complete.

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 has zero parameters, so the description need not add parameter information. With 100% schema coverage, the baseline score is 3, but the description implicitly acknowledges the absence of parameters by not mentioning any, earning a 4 as no additional value is required.

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 tool's action: 'Save a BC screenshot and return its path.' It specifies the verb (save) and the resource (screenshot), and adds a usage condition ('Use only when visual evidence matters') that further clarifies purpose. This distinguishes it from sibling tools like browser_observe and browser_act.

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 includes explicit guidance: 'Use only when visual evidence matters.' This tells the agent when the tool is appropriate. However, it does not name alternatives or provide explicit when-not-to-use scenarios, so it falls short of a perfect score.

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