mcp-obsidian

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states the tool returns statistics but doesn't describe important behavioral aspects: whether it requires authentication, how it handles large vaults (performance/rate limits), if it's read-only (implied but not explicit), or what format the statistics are returned in. For a tool with zero annotation coverage, this represents significant gaps in transparency.

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 perfectly concise at a single sentence that efficiently communicates the core functionality. Every word earns its place by specifying exactly what statistics are returned. There's no redundancy, fluff, or unnecessary elaboration for such a straightforward tool.

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?

Given the tool's simplicity (0 parameters, has output schema) and lack of annotations, the description is minimally adequate. It tells what the tool returns but doesn't provide important context about authentication needs, performance considerations, or how the statistics are calculated. The existence of an output schema means the description doesn't need to explain return values, but other behavioral aspects remain undocumented.

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 has 0 parameters with 100% schema description coverage, so the baseline is 4. The description appropriately doesn't discuss parameters since none exist, and it correctly focuses on what the tool does rather than trying to explain non-existent inputs.

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 clearly states the tool's purpose with a specific verb ('Return') and resource ('statistics about the vault'), listing the exact metrics provided (note count, word count, tag count, link count). It distinguishes from siblings like 'get_recent_notes' or 'list_tags' by focusing on aggregated statistics rather than listing individual items. However, it doesn't explicitly contrast with all siblings, keeping it at 4 instead of 5.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites, timing considerations, or compare it to siblings like 'get_orphans' or 'search_notes' that might provide overlapping or complementary data. This lack of contextual usage information leaves the agent without clear selection criteria.

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