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

The annotations already declare readOnlyHint and idempotentHint, and the description reinforces this by stating 'Read-only; never edits tasks.md.' It adds the file path, the 'next uncompleted task' semantics, and the completion-marker behavior, which are not derivable from the annotations alone. There is no contradiction with 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?

Three sentences with no filler: the action and file path are front-loaded, the read-only caveat is explicit, and routing to siblings is compressed into the last sentence. Every clause earns its place.

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 read-only retrieval tool, the description covers what it reads, what it returns, when to use it, and how it differs from related tools. It is complete enough for an agent to invoke it correctly without an output schema, since it names the required input and the two possible return outcomes.

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%, so the baseline is 3; the description adds value by singling out feature as the parameter to pass and defining it as the exact spec directory name, tying it to the path vdd/specs/<feature>/tasks.md. It does not explicitly state that the other schema parameters are ignored, but the core invocation requirement is clear.

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 opens with a specific verb and resource ('Read vdd/specs/<feature>/tasks.md and return the next uncompleted task') and explicitly covers the completion-marker case. It distinguishes itself from siblings by naming vdd_tasks and vdd_implement as alternatives, so there is no ambiguity about what this tool does.

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 gives an explicit usage window ('Use before each implementation session to keep context isolated') and names both the list-regeneration alternative and the follow-up execution tool. This is model routing guidance rather than a vague hint.

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