Expand a folded summary line back into the original message text it was built from, retrieving up to 12,000 characters for a given view line id.
Open view line id+n into the two lines it was made from. n = 1 gives the original message, up to 12,000 characters.
| Name | Required | Description | Default |
|---|---|---|---|
| n | Yes | ||
| id | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description adds genuine context beyond that: n=1 returns the original message and output is capped at 12,000 characters. It still omits what the 'two lines' output actually contains and whether truncation is silent.
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 core operation stated first and the size limit second; nothing is padded. Brevity tips into under-specification, but structurally it is tight and front-loaded.
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 two required params at 0% schema coverage and no output schema, the description needed to define both parameters and clarify the return shape. It leaves id undefined and the 'two lines' output unexplained, which is not enough for an agent to invoke this reliably.
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 0%, so the description must carry all parameter meaning, and it only partially does. It hints that n is an offset into the view (n=1 yielding the original message) but never explains what id identifies, why id has a minimum of 0, or what larger n values do.
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 uses a specific verb ("open") and resource ("view line id+n"), but the domain language "view line" and "the two lines it was made from" assumes knowledge of an internal structure. It never explains how it differs from siblings like view, read_message, or compact_read, so an agent cannot confidently pick it.
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?
There is no guidance on when to use this rather than view, read_message, or compact_read, all of which sound like overlapping read operations. The only usage-adjacent detail is the n=1 case, which describes behavior, not selection criteria.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.