Vault Search

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

The annotations already declare readOnlyHint=true, so the description only needs to add context beyond that. It adds the requirement of RESEARCH_MCP_OBSIDIAN_VAULT, the fact that it searches Markdown notes, and the return format (line numbers and snippets). This provides useful behavioral detail without contradicting annotations.

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 two sentences: the first front-loads the action and output, the second adds usage guidance and a prerequisite. Every sentence provides distinct value with no fluff or repetition of schema details, making it tightly written and easy to scan.

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 simple search tool with only two parameters and no output schema, the description covers the essential context: what is searched, what is returned, when to use it, and a required environment variable. It could potentially explain match behavior (e.g., case sensitivity) or clarify that results are capped by limit, but these are minor given the low tool complexity.

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 both query and limit have clear descriptions in the schema. The tool description does not add further parameter-level meaning, but with full schema coverage the baseline of 3 is appropriate. It doesn't need to compensate for schema gaps.

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 states a specific verb ('Search'), a clear resource ('the configured Obsidian vault (Markdown notes)'), and an explicit output ('matching files with line numbers and snippets'). This uniquely distinguishes it from sibling tools like vault-read (reading a specific note) and web-search (searching the web), as it narrows to the local Obsidian vault.

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 explicitly says when to use it: 'Use to find existing notes, lit reviews, or evidence tables before creating new ones.' It also notes the environment variable prerequisite. However, it does not explicitly name alternative tools or state when not to use it, so it stops short of a full when-to-use/when-not-to-use contrast.

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