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

Annotations already declare a safe read (readOnlyHint=true, destructiveHint=false), and the description still adds real behavior: default ordering (newest first), the return shape (excerpts), the default filtering of archived docs, and the output contract for citing docs ([[doc:ID]] on its own line, never [[board:ID]]). That is substantive disclosure beyond what the structured fields provide.

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?

The description is front-loaded with the purpose and scope, then the filtering behavior, then the citation contract, with no filler sentences. The closing board guardrail ('NEVER cite a doc as [[board:ID]]; boards are sketches') partly echoes the earlier board distinction, but it functions as a distinct output-format constraint rather than pure repetition.

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?

There is no output schema, so the description carries the burden of describing returns, and it does so (newest first, with excerpts) while also covering default filtering and the ID-citation format. For a three-parameter read-only list tool, nothing an agent needs to call or report results correctly is missing.

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 documents q as case-insensitive title matching, workspace auth semantics, and includeArchived's default false. The description largely restates these ('q narrows by title', 'Archived docs are hidden unless includeArchived'), so it adds framing but no new syntax or meaning, making the baseline 3 appropriate.

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 ('Lists the workspace's Napkin docs') and explicitly delineates the resource from its closest sibling surface ('the LINEAR surface, distinct from boards which are drawing canvases'). It also distinguishes listing from retrieval by pointing to napkin_docs_get, so an agent can separate it from both napkin_boards_list and napkin_docs_get 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?

Gives clear context: use this to enumerate docs newest-first with excerpts, then 'Fetch one with napkin_docs_get' for a single doc, and names the conditions that change results (includeArchived, q). It does not, however, address when to prefer this over search-style siblings like search_docs or list_docs, so the routing guidance is clear but not exhaustive.

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