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

Annotations already declare it is a write (readOnlyHint=false) but non-destructive and not open-world, so the safety profile is covered. The description adds real context beyond that: the created board is blank, the handover syntax is `[[board:ID]]` on its own line, and it warns that napkin_deck_write is preferable when content already exists. It does not discuss permissions or workspace-token behavior, which the schema covers instead.

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 sentences, each carrying a distinct load: what it makes, what it is not for, and how/when to use it. The exclusion and the primary trigger are front-loaded, and the handover format is given inline rather than left to a later sentence.

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 low-complexity create tool with full schema coverage and annotations covering the safety profile, the description supplies everything still missing: the emotional/practical trigger for proactive use and the exact syntax for surfacing the new board back to the user. No output schema exists, so return-value detail is not required.

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%, so the baseline is 3. The description earns above baseline by explaining what the `kind` enum values actually mean (sketch = free canvas, deck = slides) and by implying the deck case has a better sibling tool, adding semantic meaning beyond the raw enum.

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 ("Creates a blank Napkin board") and immediately scopes it with the two valid kinds ("sketch (free canvas) or a deck (slides)"). It also names the sibling it is NOT (napkin_docs_create), so an agent can distinguish it without opening either 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?

Gives explicit when-not guidance ("NOT for written documents: 'draft/write a doc, note, memo' is napkin_docs_create"), a positive trigger ("Use when the user asks for one"), a proactive condition, and a routing rule to a better alternative for the deck-with-content case ("prefer napkin_deck_write"). Nothing is left to inference.

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