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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: output reflects unsaved live state (not persisted data) and includes a document model reference. It does not say what happens with a stale or invalid pairing_id, which keeps it short of a 5.

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, the payload description is front-loaded and the sequencing rule follows. The first sentence is a long comma-chained list, but every element is informative and none is filler.

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 carries the burden of explaining return values, and it does so thoroughly: document content, paywall identity, current screen, selected node, and model reference. An agent knows both what it receives and how to act on it.

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?

There is a single parameter with 100% schema description coverage ('From pair_editor'), so the schema already carries the semantics and baseline 3 applies. The description never mentions pairing_id or its dependency on pair_editor, so it adds nothing here.

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 and states precisely what is read: the live document including unsaved changes, the paywall, the active screen, the selected node, and the model reference. It implicitly distinguishes itself from the stored-document sibling (read_doc) by emphasizing 'exactly as it is on the person's screen,' though it never names that sibling 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?

It gives an explicit sequencing rule — 'Read this before editor_set_doc' — plus a working instruction ('edit what you got — keep node ids, change only what was asked'). That tells the agent both when to call this tool and how its output feeds the follow-up call.

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