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

With no annotations, the description must disclose behavior. It explains the computation (value-area migration) but does not mention that if 'candles' are not supplied, the tool fetches data from the venue (which may involve latency or costs). The description hints at the output (direction) but omits side effects or auth requirements.

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 two sentences with no wasted words. It front-loads the core concept ('Market Profile value-area migration across sessions') and ends with a practical use case. Every sentence 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?

Given no output schema, the description should convey the return value. It implies the output is a directional assessment ('up, down, or overlapping') but does not specify format or additional details. With 8 parameters, the description lacks guidance on parameter interactions or workflow steps, leaving gaps for an agent.

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% with each parameter having a clear description. The tool description adds no parameter-specific details beyond the schema, so the baseline score of 3 applies. The description provides context for the 'lookback_sessions' parameter by mentioning 'across sessions', but no extra semantic meaning.

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 clearly states it analyzes Market Profile value-area migration across sessions to determine direction (up/down/overlapping). It provides a concrete use case question, 'is value moving higher day over day?', making the tool's specific purpose unambiguous and distinguishable from sibling workflow tools.

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?

The description gives a clear use case ('Use for is value moving higher day over day?'), implying when to apply the tool. It does not explicitly exclude alternatives or contrast with sibling tools, but the context of multi-session migration is sufficiently clear for an agent to infer appropriate usage.

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