Read a module from the editor

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

Annotations already establish readOnly, idempotent, and non-destructive behavior. The description adds meaningful behavioral context beyond those annotations: it reads unsaved editor state, can differ from the file-based read, and surface_only only works for modules open in a tab. This is exactly the kind of non-obvious behavior an agent needs to know.

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?

Three sentences with no wasted words. The most important behavioral fact (unsaved edits) is front-loaded, the sibling distinction comes second, and the parameter nuance is placed last. Every sentence earns its place.

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?

Given the output schema exists and annotations cover safety, the description provides the remaining context an agent needs: when the result differs from xlide_read_module, when to choose this tool, and the caveat about surface_only. This is complete for an agent to invoke it correctly.

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%, so the baseline is 3. The description adds value by clarifying the conceptual difference between reading through the editor and reading the modern editor's own copy, especially tying surface_only to open-tab availability. It does not deeply elaborate on pid/project, but the schema already documents those adequately.

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 states a precise verb and resource: 'Reads a module's text as the running editor holds it'. It also immediately differentiates this tool from xlide_read_module by identifying the exact difference (unsaved edits), so an agent can select it correctly without needing to inspect sibling schemas.

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 guidance is explicit: use this tool to see what the user is actually working on, and use xlide_read_module for what is in the file. The description also explains the surface_only parameter's conditional availability, telling the agent when it can and cannot be used.

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