game_screenshot

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

Annotations already cover readOnly, idempotent, and non-destructive behavior. The description adds valuable behavioral context: 'Slowest verification path' (performance) and 'Requires run_interactive' (prerequisite), which go beyond annotation data.

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?

Every sentence serves a distinct purpose: purpose, usage condition, alternatives, inline capture guidance, and prerequisite. It is concise despite covering multiple aspects, with no filler words.

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 single-parameter tool with no output schema, the description is complete: it explains what the tool does, when to use it, alternatives, and a prerequisite. The agent has enough information to select and invoke it correctly.

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% for the single optional parameter outputPath, so the baseline is 3. The description does not add parameter-level detail beyond what the schema provides, but it doesn't need to.

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 states a specific verb and resource: 'Capture a screenshot from a running interactive project.' It distinguishes itself from sibling tools by explicitly contrasting with game_state, evaluate_expression, get_runtime_errors, and send_key_sequence for inline captures.

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?

Provides explicit when-to-use guidance: 'use only when visual appearance itself matters', and names specific alternatives for other cases. It also states a clear prerequisite: 'Requires run_interactive.'

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