scan_old

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

No annotations are provided, so the description carries the behavioral burden. It communicates the key behavior: files are selected based on modification time older than a configurable number of days. However, it does not mention whether the operation is read-only, how errors or missing directories are handled, or any other scan behavior, leaving some ambiguity.

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 short sentence with no filler. It is front-loaded with the action and subject, and the default value is included as a helpful parenthetical.

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 simple two-parameter tool with an output schema, the description is mostly sufficient for basic invocation. It falls short on contextual completeness because it fails to explain when to use this tool over its siblings and does not describe any edge-case behavior or expectations.

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 schema already documents both parameters. The description adds a default value that is also present in the schema, and it clarifies the meaning of 'old' in terms of modification time, but it does not add substantial semantic value beyond the schema.

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 a specific action (scan) and resource (files not modified), with an explicit time criterion and default (90 days). It is clear enough to distinguish from sibling tools like scan_large or scan_by_ext, though it does not explicitly name the distinction.

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?

There is no guidance on when to use this tool versus the sibling tools scan_large, scan_duplicates, scan_by_ext, or summarize. The description only explains what it does, not when it should be selected or when an alternative would be better.

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