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

Annotations already mark this as a non-read, non-idempotent write, and the description adds valuable behavior beyond that: suggest and confirm before saving, don't create duplicates by checking list_skills, and the per-plan skill cap. It doesn't cover auth or rate limits, but those are not strongly implied by the annotations.

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 dense but organized: purpose first, then usage policy, then parameter semantics, then scoping. It is longer than strictly necessary, but each sentence adds decision-relevant information rather than padding.

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 five-parameter creation tool with no schema descriptions, the description covers purpose, when to use it, how to avoid duplication, parameter meaning, scoping, and plan limits. The only material omission is the enabled parameter, and the existence of an output schema means return-value explanation is not required.

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?

With 0% schema description coverage, the description carries the full explanatory burden and does so for name, description, body, and project_id, including the indexing and lazy-loading behavior. The only gap is the 'enabled' parameter, whose meaning is left entirely to inference.

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?

Opens with a specific verb and resource ('Save a reusable Agent Skill') and defines it as a how-to procedure for a recurring task, with a concrete example. It also orients the agent against sibling tools by referencing list_skills for duplicates and get_skill for body loading.

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 explicit trigger conditions: offer to save after a non-trivial procedure, confirm first, avoid silent or trivial saves, and call list_skills before creating. It also explains global vs project scoping, which is exactly the decision an agent needs to make before invoking.

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