screenReturns the rendered character grid for terminal app views when the semantic tree cannot express chart contents or layout, if app policy exposes it.
Returns the rendered character grid. Prefer tree; use this only for what the tree cannot express, such as chart contents or layout. Disabled unless the application's policy exposes the screen.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the lower bar applies; the description adds genuine behavioral context beyond them by disclosing an availability gate tied to the application's policy. It does not say whether an unavailable call errors or returns empty, 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?
Three tight sentences, front-loaded with what the tool returns, then the routing rule, then the caveat. Every sentence earns its place with no redundancy against the schema or annotations.
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?
For a parameterless read whose annotations carry the safety profile, the description supplies the return nature, sibling routing, and the availability gate — enough to call it correctly. Only the failure behavior when the screen is not exposed is left unstated, a minor gap rather than a blocking one.
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?
The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. No parameter claims are made or needed.
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 and resource ('Returns the rendered character grid') and immediately contrasts itself with the sibling tool 'tree', so an agent can distinguish the two without opening a schema. The scope of what is returned is concrete rather than a restatement of the name.
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?
Explicitly names the preferred alternative ('Prefer tree') and the narrow condition that selects this tool ('only for what the tree cannot express, such as chart contents or layout'). It also states a gating precondition ('Disabled unless the application's policy exposes the screen'), which is exactly the when-not guidance a caller needs.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.