screenshot

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

Adds context beyond readOnlyHint: specifies BLE transport, PNG format, and screen size (128x64). Contradicts nothing in annotations.

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?

Extremely concise: two sentences, front-loaded with emoji for visibility, no wasted 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?

Fully covers the tool's purpose, output (PNG), and safety profile. No output schema needed; description explains return format. No missing information for a simple read-only tool.

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?

No parameters; schema coverage is trivially 100%. Description adds no parameter-specific info, but baseline for 0 params is 4.

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?

Clear verb 'Capture' with specific resource 'Flipper's 128x64 screen as a PNG over BLE'. Distinguishes from siblings like device_info, scan, and others that are not screenshot-related.

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 'Read-only/observational (safe to auto-allow)', guiding agents to use it for observational tasks without risks. Lacks explicit mention of alternatives or when not to use, but sufficient given simplicity.

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