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

With readOnlyHint=true, the safety profile is already covered. The description adds real behavioral value: it discloses the return shape (excerpt, location, object_id, path) and explains that search works by keyword and meaning. It also positions the tool as a gateway to get_obsidian_note.

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, no filler. The main action and return value lead, usage guidance follows, and parameter/follow-up guidance is compactly appended. Every sentence earns its place.

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?

The description covers what the tool does, when to use it, how to narrow results, what it returns, and how to continue the workflow. With full schema coverage and no output schema required, nothing necessary for correct selection and invocation 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 coverage is 100%, so the baseline is 3. The description adds meaningful semantics beyond the schema by clarifying that folder is a vault path prefix (with a concrete example), grouping vault_id/folder/tag as narrowing options, and explaining that object_id and path support follow-up with get_obsidian_note.

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?

The description names a specific verb ('Search'), a specific resource ('notes synced from the user's Obsidian vault'), and the two search modes ('by keyword and by meaning'). It also distinguishes itself from the sibling get_obsidian_note by clearly stating it returns excerpts and locations, not full notes.

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 description gives explicit use-case triggers: 'when they ask what their notes say about something, or point at their vault.' It also implies when not to use it (when you need the full note, use get_obsidian_note) via the follow-up mention, though it does not explicitly list exclusions.

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