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

Annotations supply the safety profile (readOnlyHint=false, idempotentHint=false, openWorldHint=false), so the description need not restate them. It does add genuinely useful context that the call originates from the open jig itself and is not agent-driven, but it never says what the call does server-side or what happens if an agent invokes it manually.

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 short sentences, with the identifying purpose first and the action-suppressing instruction second. Nothing is padded, though the first sentence is a touch imprecise for its length.

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 annotations, a full output schema, and 100% schema coverage, the only thing the description must contribute is whether an agent should call this, and it says so plainly. What remains thin is the consequence of calling it anyway, which matters little for a tool agents are told to skip.

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% and all three parameters carry meaningful schema descriptions (event, jigId tied back to jig_open/jig_list, snapshot). The description adds no parameter meaning beyond that, so the baseline of 3 applies.

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?

"Used by an open jig to report what it shows" identifies the resource (an open jig's displayed state) and the action (report), but the phrasing is loose about what is actually recorded and for whom. An agent can tell it is a state-reporting channel rather than a query, yet the purpose is only implied rather than stated as a specific effect.

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?

The description gives an explicit negative instruction: "You do not need to call this," which is exactly the routing guidance an agent needs to avoid invoking an internal telemetry path. It stops short of naming an alternative tool for inspecting jig state (e.g. jig_get, jig_look), so it is clear but not fully comparative.

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