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

With no annotations, the description carries the full load and does well: it discloses the turn-vs-outside-turn permission model, that modifying an existing skill requires the user, the discouragement of near-copies, and a secret-handling rule (no keys or passwords). It omits what happens on a name collision or what is returned on success, which keeps it below 5.

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?

Purpose and triggers are front-loaded and every sentence carries information, but it is delivered as one dense run-on block that mixes guidance, mode rules, and formatting specs, making it slower to parse than a lightly structured version would be.

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 5-param mutation tool with no annotations and no output schema, the description covers when to use it, the permission model, all parameter meanings, and content requirements. The residual gaps (return confirmation, conflict handling on duplicate names) are modest but real.

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 0%, so the description must define all five params — and it does: name (2-5 words, no dates or one person's case), use_when (one line), body (Markdown with ## Steps and ## Watch out for), plus old (an exact piece of existing text) and new for edits. This is meaningfully more than the bare schema types.

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: saving "how to do a job" as a reusable skill for future agents. It distinguishes itself from skill_view (editing an existing skill) but only in passing, and never explicitly contrasts with skills_list, so sibling differentiation is partial rather than crisp.

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 names concrete trigger conditions (work that took several tries, a user correction, a skill that turned out wrong) and then splits behavior by context: within an agent turn only new skills can be saved, while outside a turn you must read via skill_view and supply old/new. Alternatives and the when-not path are both spelled out.

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