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

Annotations cover readOnlyHint, idempotentHint, and openWorldHint, providing safety and idempotency. The description adds useful context: it returns the list without editing the file, and the host agent applies resolutions. It doesn't mention rate limits or auth, but for a read-only local file scan those are less critical. The added clarification about the host workflow goes beyond 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?

Concise single paragraph with all key information front-loaded: phase, action, return items, behavior, usage guidance, and parameter relationship. Every sentence earns its place with no 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?

Complete for a read-only tool with a defined output schema. The description covers purpose, when-to-use, behavior, and parameter relationships. Since an output schema exists, it needn't detail return format. Nothing an agent needs 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?

Schema coverage is 100%, so the schema already documents both parameters thoroughly, including examples and constraints. The description adds a parameter relationship note ('feature must be the exact spec directory name created by vdd_specify'), which is useful but reiterates what the schema implies. Baseline 3 is appropriate when schema does the heavy lifting.

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?

States a specific verb+resource: 'Clarify an existing spec' and details exactly what it scans (vdd/specs/<feature>/spec.md) and what it returns (NEEDS CLARIFICATION markers, placeholders, ACs needing edge cases). Distinguishes itself from sibling vdd_specify by naming it and stating the opposite use case.

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?

Explicitly says when to use ('Run after vdd_specify when a spec has unresolved markers') and when not to ('to author a brand-new spec use vdd_specify instead'). Also implies the host agent applies resolutions afterward.

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