Read one chunk from a download session

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

With no annotations, the description carries the full burden. It discloses the pagination pattern and the sha256 in the final response, but does not clarify whether offset advances automatically, what happens on invalid offsets or EOF boundaries, or prerequisites like an active session. Moderate transparency.

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?

Two sentences with essential information front-loaded: the core action first, then the pagination and hash detail. Zero fluff, every clause earns its place.

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 absence of an output schema, the description explains the response contract adequately: data is base64, pagination via nextOffset, eof termination, and sha256 at the end. It does not cover error conditions or session prerequisites, but for a chunked reader this is reasonably complete.

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 67% and already describes defaults for length and offset. The description does not add any parameter-specific guidance beyond the schema; it focuses on output behavior. Baseline 3 is appropriate since the schema handles most parameter semantics.

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?

Clearly states a specific action (fetch a byte range as base64) and resource (download session). Distinguishes from siblings like file_transfer_write (write) and file_transfer_status (status) by describing the read operation and its pagination.

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 usage mechanics (repeat with nextOffset until eof) but does not explicitly state when to use this tool vs alternatives like file_transfer_status or file_transfer_open. The context is implied (within a download session) but not contrasted with siblings.

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