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

Annotations already declare readOnly/idempotent/openWorld, so the safety profile is covered. The description adds genuinely non-obvious behavior: it never edits tasks.md, returns a completion marker when no tasks remain, and returns a delegation envelope on the stateless hosted endpoint unless artifactFiles is supplied.

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?

Front-loads the phase and action, then layers usage, parameter relationships, and the hosted-endpoint caveat. Efficient overall, though the final sentence is dense enough that a reader must parse it carefully.

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?

With an output schema present, return values need no elaboration. The description covers purpose, when-to-use, alternatives, parameter linkage, and the stateless-endpoint edge case, leaving no gap an agent needs in order to call it correctly.

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 baseline is 3, but the description adds cross-tool parameter relationships: feature must match the spec directory and the returned taskId (TASK-###) is the argument to vdd_implement, plus how artifactFiles must be shaped on the hosted endpoint.

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 (read), resource (vdd/specs/<feature>/tasks.md), and precise output (next uncompleted task or a completion marker). It also names sibling tools (vdd_tasks, vdd_implement) so the agent can distinguish this from adjacent operations.

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?

Explicit when-to-use ('before each implementation session to keep context isolated') plus named alternatives: vdd_tasks to regenerate the whole list and vdd_implement to execute the returned task. Nothing is left to inference.

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