look

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

No annotations are provided, so the description carries the full burden. It does disclose the output shape (numbered elements with role/text/states/coordinates and an image), which is genuinely useful behavioral context, but says nothing about permissions, rate limits, or side effects of repeated calls.

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?

Dense but front-loaded: the core purpose comes first, then parameter semantics line by line. Every clause carries information and there is no filler, though the compressed telegraphic style slightly hurts readability.

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 3-optional-parameter observation tool with no output schema and no annotations, the description covers the return format and all parameters adequately. The main gap is the absence of any when-to-use routing relative to its many siblings.

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%, so the description must compensate, and it largely does: it enumerates each 'show' enum value with its default, explains 'query' as a text filter over elements, and defines 'region' as a zoom expressed in pixels of the last full image. Only minor ambiguity remains (e.g., region not marked as optional).

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 a concrete verb+resource ('Voir l'écran du téléphone') and specifies what is returned: numbered elements with role/text/state/center coordinates plus an image. This distinguishes it from action-oriented siblings like 'act' or 'launch', though it never names an alternative explicitly.

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?

Usage is implied (observe the screen), and the parameter explanations hint at intent (query to filter, region to zoom), but there is no explicit guidance on when to use 'look' versus 'act' or 'phone', nor any stated prerequisites or when-not-to-use condition.

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