show_board

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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, and the description adds real behavioral context beyond them: hosts supporting MCP Apps embed an interactive canvas, while other hosts fall back to ordinary tool read/write. The note that users can edit in the embedded canvas sits in mild tension with readOnlyHint, but since the tool call itself takes no parameters and mutates nothing, this is disclosure of UI behavior rather than a contradiction.

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 short sentences, front-loaded with the core action, followed by the trigger condition and host-dependent behavior. No filler or repetition of the title.

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 zero-parameter, no-output-schema tool whose annotations already cover the safety profile, the description explains what appears in the UI and what happens on hosts without MCP Apps support. It does not say what an agent should do after presenting the canvas (e.g., wait for user edits), a minor gap.

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 no parameter semantics to explain; baseline 4 applies. The description correctly implies parameterless invocation by describing a single display action.

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 gives a specific verb and resource: it displays a shared infinite canvas beside the agent conversation for direct viewing/editing. It also distinguishes itself from the ordinary read/write path used on non-MCP-App hosts, so an agent can tell it apart from get_board/draw_board without opening a schema.

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 states an explicit trigger — invoke when the user asks to open, view, show, or edit the Doodle canvas — which is clear and actionable. It does not name exclusions or explicitly route to sibling tools for pure data reads, leaving that to inference.

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