Screenshot the game

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

No annotations, so description carries the full burden. It discloses the one-shot nature (not a live view), the return behavior (image vs path when path is set), and output format (PNG). It doesn't cover auth, rate limits, or error conditions, but for a screenshot tool these are less critical and the key behavioral traits are well covered.

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?

Three sentences, front-loaded with the core action, then usage context, then the crucial distinction from live_view. No wasted words and the most important routing information is placed first.

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 2-param read-only tool with full schema coverage and no output schema, the description provides all needed context: what it returns, how path changes behavior, and when to use it vs live_view. Missing only edge-case error behavior, which is minor.

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 the schema already documents both parameters. The description adds the behavioral consequence of setting path (returns path instead of image), which is a meaningful addition beyond the schema's basic description. Baseline 3 is appropriate when schema is comprehensive, but the extra consequence is slightly helpful.

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 the specific action (take a PNG screenshot) and target (game viewport), and distinguishes itself from the sibling live_view by naming it. An agent can tell exactly what this does without reading the schema.

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?

Explicitly states when to use it (canvas/image-driven games, visual QA) and when not to (not a live view; call live_view once to let the user watch). This directly answers the 'when vs alternatives' question with a named alternative.

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