Vault Statistics

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

Annotations already declare readOnlyHint=true and idempotentHint=true. The description adds that the tool 'scans every .md file', implying performance implications, and clarifies vault selection precedence. It does not contradict annotations. However, it omits details like whether results are cached or if there are rate limits, so a slight gap remains.

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 a single paragraph with three sentences. It is front-loaded with the main purpose and key metrics. Some minor redundancy (e.g., 'Read-only' repeated from annotations) exists, but overall it is efficient and to the point. Could be slightly more compact without losing value.

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 complexity (aggregate stats across many notes) and the presence of an output schema, the description is complete. It lists the returned statistics, explains vault selection, and references sibling tools. No additional information is needed for an agent to correctly invoke the tool.

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 0% (no descriptions in input schema), but the description explains the only parameter 'vaultPath': 'unless an explicit vaultPath argument is passed, which always wins'. It also explains default behavior (session-active vault). This adds meaningful context beyond raw schema, though the exact format of vaultPath (absolute/relative) is not specified.

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 it returns aggregate statistics for the whole vault, listing specific metrics (note count, words, characters, tasks, tags, file size). It explicitly distinguishes from siblings like notes.read by noting 'For per-note statistics use ...'. The verb 'Return' and resource 'aggregate statistics for the whole vault' are specific and unambiguous.

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 explicit guidance on when to use this tool versus alternatives: 'For per-note statistics use notes.read with include: ["stats"]'. It also explains the vault selection mechanism (session-active vs vaultPath argument) and references vault.current and vault.select for context. This covers both when-to-use and alternative tools.

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