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

The description states 'Read-only; returns the list without editing the file', which aligns with the readOnlyHint annotation. It adds behavioral detail by listing the exact output items (markers, placeholders, ACs) and notes the host agent applies resolutions. This goes beyond simply echoing the annotation and provides useful operational context.

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 a few sentences that lead with the core purpose, then clarify scope and usage. It includes the workflow and an alternative tool pointer. While not overly verbose, it could be tightened—e.g., 'Read-only; returns the list without editing the file' is slightly redundant given the annotation, but it remains efficient and well-structured.

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?

It explains the input (feature directory name), the exact output (list of items to resolve), and the follow-up workflow (host agent applies resolutions). No output schema exists, so the explicit output description is valuable. However, it does not address the many other schema parameters that appear irrelevant to this tool, potentially leaving an agent unsure whether to pass them, though the guidance to 'Pass feature' implies they are optional.

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 100% with all 10 parameters individually described, so the description adds minimal value beyond the schema. It does clarify 'Pass feature (spec directory name)' tying it to the file path, but other parameters (taskId, statement, etc.) are not addressed. The baseline of 3 is appropriate given the schema already covers parameter meanings.

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 explicitly states it scans vdd/specs/<feature>/spec.md and returns specific items to resolve: [NEEDS CLARIFICATION] markers, [e.g.] placeholders, and ACs needing edge-case counterparts. It also differentiates from vdd_specify by explicitly saying 'to author a brand-new spec use vdd_specify instead', making the purpose unambiguous and distinct from siblings.

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 provides clear when-to-use guidance ('Run after vdd_specify when a spec has unresolved markers') and when-not-to-use ('to author a brand-new spec use vdd_specify instead'). However, it does not clarify conditions relative to other siblings like vdd_analyze or vdd_validate, leaving some potential ambiguity for those tools.

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