sync_index

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

With no annotations, the description carries the full burden, and it discloses real behavioral traits: a bounded chunk-backfill cap (_SYNC_INDEX_CHUNK_LIMIT), the deliberate refusal to drain the whole backlog in one call, and the rebuild-via-scan behavior. It stops short of stating whether the rebuild replaces or preserves existing index state and what the cost/runtime profile looks like.

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-loads the core action in sentence one, then the when-to-run conditions, then the edge-case escape hatch. Every sentence carries distinct information with no redundancy.

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 values need no explanation, and the description covers triggers and the backlog-limit caveat. The one gap is the mutational effect on the existing index (rebuild vs. merge), which matters for a tool with no annotations.

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 there is nothing for the description to disambiguate (baseline 4). The mention of _SYNC_INDEX_CHUNK_LIMIT is an internal constant, not an argument, so no parameter semantics are needed.

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 ('Rebuild') and resource ('the DuckDB index by scanning all vault markdown files'), making the operation unambiguous. It is distinguishable from siblings like sync_notes and sync_chunks_tool by naming exactly what gets rebuilt and the secondary chunk backfill.

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?

Explicitly names the trigger conditions ('after adding notes manually, or when setting up on a new machine') and routes the agent to an alternative ('run sync_chunks_tool() separately to drain the rest') when the outstanding backlog exceeds the internal limit.

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