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

Annotations already indicate this is a write operation (readOnlyHint=false, destructiveHint=false); the description adds real behavioral context: the default path behavior, the session-scoped convention, the one-of content requirement, and the signed-in-account prerequisite. It doesn't address possible name conflicts or overwrite behavior, but this is a minor gap for a 'new file' creation 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?

Three sentences, no filler: the first establishes the core action, the second provides the default-path behavior, and the third covers the content exclusivity. Every sentence 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?

For a straightforward single-file creation operation, the description covers the essential call-time decisions: path default, content encoding choice, and auth requirement. It does not describe the success response, but there is no output schema and the information needed to invoke the tool correctly is present.

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%, so the baseline is 3; the description adds value by explaining the path default's purpose ('keeps agent output separate from user uploads') and reinforcing the mutually exclusive content_text/content_base64 choice. This goes beyond simply restating parameter names.

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 names a concrete verb and resource: 'Save a new file the agent has produced ... into Octopus.' It also scopes the tool to agent-generated output, which sets it apart from the other octopus_* operations like read, delete, move, and list without needing to compare names.

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 clearly states the intended use case—persisting files the agent has generated—and gives a strong convention signal by defining the /agent/{session}/ default so agent output stays separate from user uploads. It does not explicitly enumerate when-not-to-use or alternatives, but there is no directly overlapping sibling write tool, so explicit exclusions are less critical.

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