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

Annotations declare destructiveHint=true, and the description backs this with real consequences: edits 'fail loudly rather than clobbering a doc somebody else is typing in,' body 'replaces the WHOLE document,' archived toggles gallery visibility. It doesn't cover failure modes like concurrent-edit conflicts or the needs_confirmation/approvalId flow its annotations imply, but the destructive-risk context is strong.

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 default recommendation (edits) before the riskier alternatives, and each mode gets a compact clause. Slightly dense in one paragraph, but every sentence either routes a decision or warns of a consequence.

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?

Covers the mutation modes, the ordering constraint for edits ('applied in order. All must match or none are applied'), and the prerequisite read. For a 10-param destructive tool with no output schema, this is adequate, though it omits the approvalId/needs_confirmation path and workspace-token nuances the schema describes.

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 80%, so the schema carries most param detail. The description still adds value by naming which param does what ('`append` adds a section at the end', archived semantics), but it doesn't explain workspace/visibility/approvalId quirks beyond what the schema already documents.

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 (edit) and resource (Napkin doc), then enumerates the exact mutation modes (edits, append, body, retitle/describe/visibility/archive). An agent can distinguish this from napkin_docs_create and napkin_docs_get immediately.

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 prioritization among alternatives: `edits` is 'the SAFEST option and the one to reach for by default,' `body` is 'a last resort.' It also mandates reading the doc first via napkin_docs_get, which is a concrete precondition no other tool provides.

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