Open project file

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

Beyond annotations (destructiveHint=true, idempotentHint=true), it discloses what actually gets destroyed ('replaces the current project'), the irreversible consequence ('No undo step - the command history starts over'), and the required flag under pending unsaved changes. This is exactly the extra context annotations cannot carry.

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?

Four dense sentences, each load-bearing, with the destructive replacement front-loaded. The closing sentence about 'note' is the one arguable redundancy since an output schema exists, but it is short and orients the caller.

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 destructive open/replace operation the description covers side effects, the undo posture, the discarded-state requirement, and the sibling alternative; return values are covered by the output schema. Nothing needed to call it safely is missing.

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 100% and both parameters are documented there, so the baseline is 3. The description adds conditional meaning the schema lacks: discardChanges:true is required only when unsaved changes are pending, not merely an optional toggle.

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?

States a specific verb and resource ('Opens exactly one project file (.rpj)') plus the scope limit on count and file type. It explicitly separates itself from the portfolio sibling by naming the file extension it refuses, so an agent can route correctly without opening either schema.

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?

Gives an explicit when-not ('A portfolio (.rpp) is refused') and names the correct alternative, rillsoft_portfolio_file_open. It also states the precondition that selects discardChanges:true, covering the only non-obvious call path.

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