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

Annotations already declare readOnlyHint=true, idempotentHint=true and non-destructive, so safety is covered; the description adds real value by disclosing the payload contents (baseline, latest capture, diff magnitude, recent captures). It stops short of noting what happens when no baseline exists or how recent-capture history is bounded.

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?

A single front-loaded sentence listing the returned artifacts with zero filler; every clause carries information the agent needs to decide to call it.

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?

With no output schema, the description must convey return content, and it does so concisely and accurately for a read-only tool whose safety profile is already in annotations. Minor gaps remain on error/prerequisite conditions and the size of the capture history.

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 100% and both parameters are documented in-schema, including the DESKTOP/MOBILE enum and the default, so the baseline of 3 applies. The description adds nothing about parameter meaning beyond what the schema states.

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 specific verb (Show) and resource (a monitor's visual check) and enumerates the four things returned: baseline, latest capture, diff amount, recent captures. This clearly separates it from mutation siblings like vs_visual_accept_baseline or vs_visual_capture_now, though it never names them 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 only implied: an agent can infer this is the read-side counterpart to capture/accept tools, but the description never says when to call it versus vs_monitors_get or vs_monitor_report_get, nor does it mention prerequisites such as the monitor having visual checks enabled.

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