list_documents

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states that the tool lists every indexed document with size and chunk count, which conveys the core behavior. However, it does not mention pagination, ordering, or whether the result is returned as a single batch – relevant for large corpora. Since it's a read operation with no side effects, this is acceptable but not exhaustive.

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 exactly two sentences: the first states the function, the second gives the usage context. It is front-loaded with the core action and every sentence earns its place. There is no fluff or 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?

Given the tool's simplicity (0 params, no output schema, no annotations), the description provides sufficient information: what it does (lists documents) and what fields are included (size, chunk count). It also gives usage context. It lacks explicit return format, but the mention of fields implies the structure. For a straightforward list tool, this is adequate.

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 zero parameters and the schema is an empty object, so schema description coverage is 100%. With no parameters to describe, the description adds nothing parameter-specific, and the baseline of 4 applies because there is nothing to compensate for.

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 states a specific verb ('list'), a precise resource ('every indexed document'), and the output fields (size and chunk count). It clearly distinguishes this from search_documents (searching), get_chunk (retrieving a chunk), and get_document (retrieving a document) – it is the corpus-level overview tool.

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?

Provides explicit guidance on when to use it: 'Use it to find out what this corpus actually covers before searching.' This implies it is a preliminary discovery step and implicitly differentiates from search_documents, which would be used for actual searching. It doesn't explicitly name alternatives, but the context is clear.

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