Vault guide

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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds genuine behavioral context beyond them: the response is two-part, and it discloses the fallback path when `CLAUDE.md` is absent (instructions for creating one), which an agent could not predict from annotations or schema.

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 core claim, then a clean two-item enumeration; every line maps to a real part of the response. Slightly longer than strictly necessary, but the structure makes it scannable and nothing is redundant.

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?

An output schema exists, so return-value shape needn't be restated, and the description still gives enough of the content outline plus the missing-`CLAUDE.md` fallback for an agent to know what it will receive. For a zero-parameter read of static documentation, nothing material 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?

The tool takes zero parameters, so the baseline is 4 by rule; there is no parameter semantics to explain and the description correctly spends no words on them.

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 two-part guide') and enumerates exactly what the two parts contain, including concrete topics (wikilinks, frontmatter, callouts, tag taxonomy). No sibling tool returns documentation content, so it is unambiguously distinguishable from read_note, list_notes, or get_tags.

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?

The phrase 'for working with this Obsidian vault' implies it is a reference to consult before authoring content, but the description never states when to call it versus alternatives, nor does it say it should be called before create_note/edit_note/set_frontmatter. Usage is inferable rather than explicit.

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