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

Annotations already declare readOnly/non-destructive/closed-world, so the safety profile is covered. The description adds meaningful context beyond structured data: pen strokes return as a point count rather than raw points, and the returned ids/coordinates are the exact inputs napkin_draw expects. Doesn't cover pagination or size limits, so not 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?

Front-loaded with the primary return behavior, then constraints, then alternatives. Every sentence carries distinct information with no redundancy, and emphasis (TARGET, LOOKS) aids scanning.

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 read-only board-fetch tool with annotations covering safety and no output schema, the description supplies the return shape, the downstream integration path, the pen-stroke caveat, the id source, and the sibling alternative. An agent has everything needed to select and 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 coverage is 100%, so boardId and workspace are already documented by the schema (including sourcing for boardId). The description reinforces that board ids come from napkin_boards_list but adds no format or syntax detail beyond the schema, so baseline 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?

States a specific verb and resource ('Returns a board's shapes as data') and enumerates the returned fields (id, kind, position, size, text). It explicitly distinguishes itself from napkin_boards_view ('what the board LOOKS like') and connects to napkin_draw, so an agent can tell it apart from siblings.

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 states the use case (to TARGET a shape to change or remove via napkin_draw updates/deletes) and names the alternative tool with its distinct condition (napkin_boards_view for visual appearance). It also notes the id source (napkin_boards_list), leaving nothing to inference.

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