Vision Grounding

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

The description adds real behavioral context beyond the annotations: coordinate mapping (normalized1000 -> original stored/oriented pixels), the caveat that crop verification does not confirm correct identification, and that empty detections are valid abstentions. However it omits the significant two-phase workflow implied by dry_run (default true) and authorize_submission (default false), and does not mention cost/limits or open-world submission implications flagged by openWorldHint=true.

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?

Three tight sentences, front-loaded with the core purpose, with no filler. It is slightly jargon-dense ('exact transmitted preparation', 'oriented source grid'), which costs a little readability but does not waste space.

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?

An output schema exists, so return values need not be explained, and the nested request schema is well described. Still, for a tool whose default behavior is a dry-run plan with an explicit submission grant, the description should say more about the dry_run -> authorize_submission flow to be complete for correct invocation.

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%, so the baseline is 3. The description reinforces the coordinate-space semantics ('Normalized1000 boxes map through the exact transmitted preparation to original stored/oriented pixels'), but the equally important dry_run/authorize_submission and backend/limits controls are left entirely to the schema.

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 concrete verb+resource+output ('Locate objects with strict inferred boxes and optional actual original-pixel crops'), which is clear and actionable. It does not, however, differentiate this tool from plausible siblings such as media_ground_events, image_segment, or vision_chat, leaving the agent to infer which grounding-family tool applies.

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?

There is no guidance on when to use this tool versus alternatives, and no prerequisites or exclusions are stated. Given several overlapping detection/grounding/content-analysis siblings, the agent gets no routing help from the description.

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