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

The annotations already include readOnlyHint, idempotentHint, and destructiveHint. The description adds useful context beyond these: a specific Mk4 engine, a capped 0-100 output, parity with related engines, and a performance characteristic. No contradiction with 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 short, well-structured, and front-loaded. It communicates purpose, engine, output range, parity, and performance in three sentences with no wasted words.

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 one-parameter tool with complete schema coverage and a description that explains the returnable range, the definition is largely sufficient. There is no output schema, but the return format is stated clearly, so an agent has enough information to invoke the tool and interpret the result.

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 input schema covers the single content parameter fully, including details about [faf] extraction. The tool description does not need to add parameter detail. With 100% schema description coverage, a baseline of 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?

The description clearly states that the tool scores .faf YAML content, uses a specific engine, and returns a 0-100 capped score. This is a specific verb+resource combination. It does not explicitly distinguish itself from sibling tools like faf_validate or faf_get_tier, but its core purpose is unmistakable.

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 says what the tool does but gives no guidance on when to choose it over the many sibling tools listed, such as faf_validate or faf_estimate_tokens. The parity-testing note is useful technical context, but it does not route the agent toward or away from alternatives.

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