files_index

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

The description notes 'no leaf content' and 'cheap-first retrieval', indicating the tool returns summaries only and is low cost. Since no annotations are provided, the description carries the full burden; it does not contradict any annotations. However, it omits details about rate limits, authentication, or side effects, though these are not critical for a read-only index tool.

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 short sentences that are front-loaded with the core purpose and usage recommendation. Every sentence adds value, with no redundancy or unnecessary information.

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 has 9 parameters and no output schema, the description is minimalist. It captures the high-level intent but lacks details on output format, parameter usage, and behavioral boundaries. It is adequate for a simple index tool but incomplete for fully autonomous use.

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?

With 9 parameters and zero schema description coverage, the description provides no explanation of parameters like limit, corpus, corpora, database, filetype, etc. This is a significant gap, as the agent would need to infer parameter meanings from names alone.

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 returns file-level summaries for triage as a cheap-first retrieval primitive, distinguishing it from file_search and file_get. It explicitly says 'Use BEFORE files_search to decide which files are worth deep-reading', differentiating among sibling tools.

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?

It provides explicit guidance on when to use: 'Use BEFORE files_search to decide which files are worth deep-reading'. It also characterizes the tool as 'cheap-first retrieval', implying it should be used before more expensive operations.

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