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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the description's 'Read-only' reinforces but doesn't add much. However, it adds valuable behavior beyond annotations: the effect of omitting both availableTools and capabilities (returns per-phase requirements without the present/missing comparison), and the alias relationship. No contradiction with 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?

The description is dense but every sentence earns its place: purpose, read-only nature, usage timing, alternative tool, and parameter handling. It is front-loaded with the core purpose and avoids fluff or repetition.

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?

Given the tool's complexity (10 parameters, nested objects, no output schema), the description covers the essential decision-making context: when to use, how to pass the critical parameters, and what happens with omissions. The return format is only described as 'capability report,' which is slightly vague, but annotations already cover the safety profile, and the schema documents all parameters. This is complete enough for an agent to invoke 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. The description adds meaning for two key parameters (availableTools and its alias capabilities) and explains the omission behavior, which is helpful. It does not elaborate on the other 8 parameters, but the schema already documents them fully. The added alias and omission context slightly exceeds the baseline, but not enough to push to 4.

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 uses a specific verb ('Report') and clearly identifies the resource: which tools/MCPs each VDD phase requires vs treats as optional, and which are present vs missing. It explicitly distinguishes from vdd_trace by purpose (capabilities vs artifacts), making it easy for an agent to select the right tool among 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 states exactly when to use this tool: 'Run before vdd_strategize to plan research-subagent dispatch, or when a phase fails for lack of a tool.' It also names the alternative (vdd_trace) and the condition for choosing it, providing clear when/when-not guidance.

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