Read a file without loading it into context

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

With no annotations provided, the description takes on the burden of behavioral disclosure. It transparently explains the offload behavior (returns a digest, not full contents) and mentions the handle, but does not cover edge cases like file access errors or handle expiration. Still, the core behavior is well disclosed.

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 two sentences, immediately front-loading the main behavior and return value, followed by concise usage guidance. Every sentence adds value 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?

The description covers purpose, usage, and return format (digest components, handle), and points to alternatives for full content. It is fairly complete for a simple read/offload tool, though it omits details about the label parameter and handle lifecycle. Given no output schema, this is a reasonable level of 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?

The schema lists two parameters (path, label) with no descriptions, and the description does not explain either parameter. 'path' is implied by the tool name, but 'label' remains completely unexplained. With 0% schema coverage, the description fails to compensate.

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 reads a file and returns a digest and handle, explicitly contrasting with a normal file read by avoiding full content in the window. It also distinguishes itself from offload_fetch by indicating when to use each.

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 explicitly advises to prefer this tool over a normal file read for large files, and directs the user to offload_fetch or the compaction://blob/{handle} resource when the full body is needed. This gives clear when-to-use and when-not-to-use guidance.

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