frame

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

With no annotations, the description carries the full burden but says nothing about read-only behavior, side effects, permissions, or failure modes. It confirms that crop exists and is for small detail, but does not describe what state the call changes or what the return looks like.

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 text is brief and the crop detail is front-loaded, but 'Full-resolution frame at a time' is a fragment that reads more like a note than a complete purpose statement. It is concise but under-specified, forcing the agent to infer too much from a single sentence.

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 tool with 3 parameters, 2 required, 0% schema description coverage, no annotations, and no output schema, the description is far too thin. It explains crop but leaves the required timing parameter and the watch identifier completely undocumented.

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 0%, so the description must explain all three parameters. It does an excellent job on crop (pixel vs. fractional coordinates), but completely omits the required 'at' and 'watch_id' parameters, leaving their meaning and format unknown.

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 implies retrieving a full-resolution frame, but uses a noun phrase rather than a specific verb and never states what resource it operates on (a watch). It is distinct from siblings like zoom or image, but the core action is only inferred, not stated.

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 only usage hint is 'for reading small detail,' which explains why crop exists but not when to choose frame over look, zoom, image, or images. No alternatives or exclusions are named, leaving the agent to guess.

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