screenshot_to_disk

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

With no annotations, the description carries the burden of behavioral disclosure. It mentions saving to disk and returning a file path, which is core behavior, but does not cover potential side effects (e.g., disk cleanup, overwriting, permissions) or error conditions. The token-saving benefit is useful context but not a behavioral trait in the safety sense.

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 exactly two sentences. The first sentence states the primary purpose, and the second adds a practical benefit and follow-up action. It is front-loaded, efficient, and contains no irrelevant 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 simple tool with 4 optional parameters and no output schema, the description covers the main outcome (saves to disk, returns path) and gives a key optimization tip. It lacks explicit differentiation from sibling tools and does not address potential errors or edge cases, but the core functionality is adequately described.

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?

Schema description coverage is 100%, so baseline is 3. The description does not elaborate on parameter specifics, but it implies the tool produces a screenshot file; the schema already documents all parameters (format, quality, fullPage, directory) with individual descriptions. No additional semantic value is added.

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 ('Takes a screenshot, saves it to disk, and returns the file path') with a specific verb and resource. It does not explicitly mention sibling tools, but the focus on saving to disk and returning a file path differentiates it from common alternative approaches like returning base64.

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 provides usage context by highlighting token savings ('Saves ~3000-5000 tokens per screenshot compared to returning base64') and instructs how to inspect the file ('Read the file with read_file if you need to inspect it'). It gives an implicit alternative (returning base64) but does not explicitly name or exclude sibling tools.

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