measure_depth_info

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

With no annotations, the description carries the burden and does so well: it discloses supported input formats and, crucially, the semantics of accuracy='relative' (needs a reference object) and intrinsics_origin='assumed' (FOV is a guess, sizes capped at low confidence with wide +/-). This is genuine behavioral context. It does not cover permissions or rate limits, but those are not relevant to a local file inspection tool.

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 purpose is front-loaded in the first sentence, with format details and field semantics following. It is dense but every clause adds information; the only mild redundancy is restating the output fields that the output schema already carries.

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 needn't be spelled out) yet the description still enumerates the returned fields and explains the ambiguous ones, which makes it complete for an agent deciding whether to trust the file before measuring. The duplicated field listing is the only minor inefficiency.

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% and the single 'path' param is undocumented in the schema, so the description must compensate. It does so by listing exactly what path accepts (HEIC/HEIF, TIFF, 16-bit PNG, NPZ, JPEG, or a capture-app bundle passed as a folder or .zip), which is the key ambiguity for this parameter.

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 opens with a specific verb and resource: 'Check what a photo or depth file contains BEFORE measuring from it.' It clearly distinguishes itself from the measure_* siblings as a pre-flight inspection step, and it enumerates supported formats (HEIC/HEIF, TIFF, 16-bit PNG, NPZ, JPEG, capture-app bundle).

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?

'BEFORE measuring from it' gives explicit timing guidance that places this tool upstream of the measurement tools, and 'A file with no depth is a plain photo: see advice for the options' tells the agent how to proceed in the degenerate case. It stops short of naming specific sibling tools to switch to, so it is context-rich but not fully explicit about alternatives.

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