index_local

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

Beyond the annotation readOnlyHint:false, the description discloses concrete side effects: 'loads rows into SQLite' and 'skips re-indexing if file unchanged.' It also clarifies the profiling behavior ('Profiles all columns, detects types, computes statistics'), providing actionable transparency about the tool's processing and incremental nature. It stops short of covering error cases or exact return values, but the disclosure is solid.

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 three sentences, front-loaded with the core action ('Index'), and each sentence earns its place: supported formats, what the index does, and the incremental option. No fluff or redundancy; it is efficiently structured for quick comprehension.

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 moderate complexity (8 params, no output schema), the description covers the essential context of what happens during indexing and the incremental behavior. However, it omits the return value of the tool (e.g., whether it returns an index ID or just confirms success) and does not mention how to subsequently use the indexed data (e.g., with run_sql or get_rows). These omissions leave a minor gap in completeness.

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%, meaning all eight parameters are described in the input schema. The tool description adds minimal beyond this: 'Set incremental=true (default) to skip re-indexing if file is unchanged' restates the schema's parameter description rather than adding new semantics. Since the schema carries the full burden, a baseline of 3 is appropriate.

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 starts with a specific verb+resource: 'Index a local data file (CSV, Excel, Parquet, or JSONL).' It clearly differentiates from the sibling 'index_repo' by specifying 'local data file' and enumerating supported formats. The follow-up sentence details what indexing entails (profiling, type detection, statistics, SQLite load), leaving no ambiguity about the tool's function.

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 implies when to use the tool ('for fast filtered retrieval') but provides no explicit guidance on when not to use it or how it compares to alternatives like 'index_repo' or other data ingestion tools. It does not state prerequisites (e.g., file accessibility) or mention better-suited tools for remote files or non-local data, leaving usage context implicit.

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