active_note

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does convey that the operation is a read/return operation, which implies non-mutating behavior, but it doesn't say what happens if no note is open or whether the returned content includes metadata beyond the raw contents.

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 a single, direct, front-loaded sentence with no filler or redundant information. Every word contributes to defining the tool's purpose and behavior.

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 parameterless tool with an output schema, the description is sufficiently complete to guide invocation. It states what the tool returns and the context in which it applies, and it doesn't need to explain return values because the output schema already provides that structure.

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, so there is no parameter semantics for the description to clarify. With 100% schema coverage and an empty properties object, the description's silence on parameters is appropriate and complete.

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 uses a specific verb ('Return') and a specific resource ('contents of the note currently open in Obsidian'). This clearly distinguishes it from siblings like read_note (which reads a note by identifier/path) and list_notes, because it targets the contextually active note rather than a user-specified one.

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 gives clear context: this tool is for retrieving the note currently open in Obsidian. It doesn't explicitly mention when not to use it or name alternatives such as read_note, but the condition ('currently open') is enough for an agent to infer the appropriate situation.

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