capture_camera

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

With no annotations, the description effectively explains the action (capture frame), return type (JSON string), and potential error. It mentions the prompt is reserved for future use, adding transparency. It does not cover edge cases like disconnection, but the prerequisites address the main constraint.

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?

The description is extremely concise, with no redundant information. It front-loads the core action and uses bullet-style Args/Returns for clarity.

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?

Given the tool's simplicity, the description covers the essential: what it does, prerequisites, return format, and parameter. The presence of an output schema further reduces the burden, though error specifics are not detailed.

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 coverage is 0%, but the description explains the single parameter 'prompt' as 'Optional prompt (reserved for future use)', adding meaning beyond the schema's bare type and default.

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 'Grab the latest frame from connected phone camera' with a specific verb and resource, clearly distinguishing it from sibling tools like capture_screen and capture_window.

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?

The description explicitly notes 'Only available in personal mode' and 'Requires phone to be connected via show_pairing_qr() first', giving clear context and prerequisites. It does not provide explicit alternatives, but the restrictions are well-defined.

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