telos.proof.visual

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

With no annotations provided, the description carries full burden and does disclose the key traits: read-only boundary, zero-auth, no external side effects beyond local subprocess reads, and a no-physical-calibration-overclaim scoping constraint. It stops short of describing return-packet fields or runtime/fixture requirements, so it is good but not exhaustive.

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?

Two sentences, front-loaded with the usage condition and the safety boundary. The first sentence is dense with jargon ('fixture-backed visual-truth proof packet... embedded sRGB samples') but each clause contributes scope or behavior rather than padding.

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 zero-parameter tool with no output schema and no annotations, the description covers what is produced ('Returns a JSON visual-truth proof packet') and the safety profile. It does not enumerate packet contents or fixture prerequisites, but nothing essential for correct invocation is missing.

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?

The tool takes zero parameters, so there is no per-parameter meaning for the description to add. Baseline 4 applies; nothing more is warranted.

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 names a specific resource — a 'fixture-backed visual-truth proof packet' — with color/luminance measurements recomputed from embedded sRGB samples, and the 'no physical-calibration overclaim' qualifier implicitly separates it from calibration siblings. The verb is implied rather than stated ('Use when a host needs...'), but an agent can tell this apart from telos.proof.research and telos.proof.build.

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?

It gives a usage trigger ('use when a host needs the fixture-backed visual-truth proof packet'), which implies scope, but never names an alternative tool or a when-not condition. The boundary against telos.display.calibration and the other proof siblings must be inferred.

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