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

Annotations already declare readOnlyHint and idempotentHint, but the description adds real context beyond them: it draws the side-effect boundary (the host agent, not the tool, performs edits, verification, and commit) and discloses a degraded mode — without artifactFiles the tool returns a delegation envelope rather than real task text. That fallback behavior is not inferable from annotations or schema.

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-loaded with phase and behavior, then constraints, then parameter relationships — a sensible ordering with no filler sentences. Minor redundancy: vdd_get_next_task is invoked twice in adjacent clauses ('after vdd_get_next_task' and 'use vdd_get_next_task instead'), which could be tightened.

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 3-parameter, nested-object tool with an output schema, the description covers everything an agent needs: purpose, sequencing, exclusions, the stateless-endpoint requirement, and the failure mode. Since an output schema exists, it correctly does not waste space describing return values in detail.

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 earns above that by documenting parameter relationships the schema does not state — taskId's provenance from vdd_get_next_task and the TASK-### format, the requirement that projectRoot match earlier phases, and the concrete artifact list (constitution.md, spec.md, plan.md, contracts/, tasks.md) expected in artifactFiles.

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 and resource (prepare one task for implementation) and names exactly what it loads (constitution, spec, plan, contracts) and returns (implementation instruction plus impact-chain commit-message format). It explicitly distinguishes itself from the closest sibling, vdd_get_next_task, so an agent can route between them without opening either schema.

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?

Gives ordering ('after vdd_get_next_task'), concurrency guidance ('run one task at a time'), an explicit exclusion ('for read-only inspection of tasks use vdd_get_next_task instead'), and a conditional branch for the hosted endpoint. This is about as complete a when/when-not/alternative statement as a tool description gets.

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