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

Annotations already declare the tool read-only, idempotent, non-destructive, and closed-world, so safety is covered. The description adds a vague promise of a 'fresh session' plus latest preview and export, but doesn't say whether fetching state has side effects (e.g., starting a session) or when 'fresh' is recomputed. A 3 reflects modest added context against strong annotations.

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?

It is a single short sentence with no padding, but it is not front-loaded with a clear action and the phrase 'For Cardboard's card' is opaque. Brevity is achieved partly by omitting essential context.

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 should clarify what 'session', 'preview', and 'export' contain and whether the operation is expensive or has side effects. It leaves the agent guessing about the return structure and the meaning of 'fresh session'.

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%, and the schema already explains both 'project' and 'render'. The description adds no parameter meaning beyond the structured fields, so the baseline of 3 applies.

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 resource ('Cardboard's card') and lists returned components (session, preview, export), but never states a verb and gives no indication of what 'Cardboard' or 'card' means. An agent cannot distinguish this from show_preview or project_status from the text alone.

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 when-to-use guidance, no mention of alternatives like show_preview or project_status, and no prerequisites. The only hint of context is the schema note about cards that play rendered files, which does not come from the description itself.

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