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

Annotations declare destructiveHint=true, and the description adds the critical context of WHAT gets destroyed: 'Overwrites tasks.md'. It also discloses the prerequisite (plan.md) and the output format details (references AC and contracts, sized S/M/L, marked [P]), going well beyond the annotation's bare destructive flag.

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 dense sentences, each earning its place: the core action with output location and format, the destructive side-effect plus prerequisite and workflow sequencing, and the sibling-tool routing. The most important constraint (what it does) is front-loaded.

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?

The description covers the core contract well—action, output path, format, destructive behavior, prerequisites, and alternative. It loses a point because with 10 parameters and no output schema, the description never disambiguates which of the seemingly generic/shared parameters are relevant to task generation, which could mislead an agent invoking the call.

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 of 3 applies even though the description adds no per-parameter detail. However, several schema parameters (taskId, statement, researchFindings, actionItemId) appear irrelevant to generating tasks and the description does not clarify which parameters actually apply to this tool.

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: 'Break the plan into atomic test-first tasks in vdd/specs/<feature>/tasks.md'. The scope is precise (VDD Phase 6, writes to tasks.md) and explicitly differentiates from the sibling tool vdd_get_next_task, so an agent can distinguish it without opening schemas.

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?

Provides explicit when-to-use conditions ('Requires plan.md; run after vdd_plan') and an explicit when-not-to-use alternative ('To fetch the next uncompleted task from an existing tasks.md use vdd_get_next_task instead of re-running this'). 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.