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

Beyond annotations (readOnly/idempotent/destructive), the description discloses no network, no side effects, safe to call repeatedly, and explains that validation errors are returned in the result rather than as schema rejections. It also defines the semantics of findings (code/message/fix), warnings (advisory), and info notes, which is exactly the behavioral context an agent needs.

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 long but dense, and every sentence earns its place: purpose and timing are front-loaded, error categories are concrete, result semantics are explicit, and the safety note is valuable. There is no filler or redundancy.

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 validation tool with a rich output schema and one flexible input, the description covers the purpose, timing, result contract, warning/info semantics, and safety profile. Nothing needed to call it correctly 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?

The only parameter, program, has 100% schema description coverage, including the crucial 'any shape — validation errors come back in the result' behavior, so the tool description does not need to compensate. The description itself does not add much about the parameter beyond referring to the program, so a baseline 3 is appropriate.

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 action and object: 'Check a Rhylthyme program for structural and scheduling errors' and positions it temporally 'BEFORE visualizing or saving it', which separates it from sibling tools like visualize_schedule and save_program. It also enumerates concrete error categories, so an agent knows exactly what domain this validation covers.

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 explicitly states when to call it ('BEFORE visualizing or saving it') and that it is pure computation safe to call repeatedly. It does not name alternatives such as analyze_schedule or calibrate_program or give explicit when-not-to-use conditions, so it stops short of full routing guidance.

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