screenshot

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

With no annotations, the description carries the full burden, and it does disclose real behavior: it writes a file to disk (a side effect) and also returns the image bytes. However, it omits whether an existing file at 'path' is overwritten, permission/auth requirements, and scaling behavior, leaving meaningful behavioral context unstated.

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?

Two short sentences, zero filler, with the default behavior (full-page) and output behavior front-loaded. Every clause earns its place.

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 an 11-parameter, zero-annotation tool with no output schema, the description covers the core action and the disk-write plus image-return behavior, which is solid. It still leaves the read vs read_screenshot relationship and file-overwrite/concurrency semantics unexplained, so it is adequate but not 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?

Schema description coverage is 100%, so all 11 parameters are already documented in the schema, setting the baseline at 3. The description only adds light framing ('full-page (default)', format options, image returned for reading) and no syntax or default details 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 and resource ('Capture a full-page screenshot') plus the scope (current page or a URL), so the action is unambiguous. It does not differentiate itself from siblings, notably read_screenshot, and the phrase 'returns the image so it can be read' arguably muddies rather than clarifies the boundary.

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?

Usage is implied: use when you want to capture the current page or navigate to a URL and grab a screenshot. There is no explicit when-not guidance and no routing against siblings like read_screenshot or open_url, which is the main gap given the potential overlap.

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