cos_digest_regenerate

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

Beyond the annotations (idempotent, non-destructive), the description reveals the digest's size limit, rolling-content nature, and the fact that it can be truncated. It also sets expectations with the return envelope `{path, size_chars, truncated, status}`.

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 front-loaded with the core action, then provides compact context, Args, and Returns sections. Every sentence contributes value with no repeated schema information.

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 single-optional-param tool with an output schema, the description covers purpose, file location, content semantics, parameter behavior, and return shape. No meaningful gaps remain.

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 0%, but the description fully compensates by explaining `project_root` means "Override project root" and that an empty/default value uses cwd. This is exactly the semantic information an agent needs beyond the bare 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 opens with a specific verb+resource: "Refresh `.coding-os/digest.md` from current memory state," which is precise and distinct from all sibling tools. It further explains what the digest contains, leaving no ambiguity about the tool's function.

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 states the digest is read at session-startup to provide a memory anchor before retrieval, giving clear context for when regeneration is relevant. It does not explicitly name alternatives or exclusions, but no sibling tool competes with this digest-regeneration function.

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