screenshot

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

With zero annotations the description carries the full burden, and it does disclose meaningful traits: what is included in the capture (HUD, menus, overlays) and that the image is returned inline rather than written to a shared directory. It stops short of latency/cost, whether the call blocks the game loop or requires a render tick, and whether capture works while paused.

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, front-loaded with the capture scope and followed by the return mechanism. Every clause earns its place and nothing is redundant.

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 zero-parameter, no-output-schema tool this is nearly complete: it explains what is captured and that an image comes back directly. A minor gap remains around the image format/size or which content block carries the payload, which matters since there is no output schema to describe the 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 declares zero parameters, so there is nothing for the description to disambiguate; baseline for a parameterless tool is 4. The description correctly avoids inventing parameters and instead spends its words on scope and return behavior.

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?

Specific verb ("Capture") plus a precisely scoped resource ("the actual Minecraft framebuffer including HUD, menus and overlays"). The word "actual" implicitly contrasts with a clean/render-only capture, and no sibling tool (execute, read_output, stop, chat) could be confused with it, though it never names an alternative explicitly.

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 rather than stated: an agent infers it should call this when it needs to see the current game screen. The note that "no shared screenshot directory is needed" removes a workflow blocker, but there is no explicit when-to-use, when-not-to-use, or comparison against siblings such as read_output.

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