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

Annotations already declare readOnlyHint, idempotentHint and non-destructive, so the safety profile is covered. The description adds real behavioral value: the session default and the tier/entitlement gate (free: SPY/QQQ; Pro: any ticker), which is not in annotations or schema. It does not describe pagination or refresh cadence, so a solid 3.

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?

Four compact sentences, front-loaded with what the tool returns, then when to use it, then defaults and access tiers. Every sentence earns its place with no filler.

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 read-only, three-parameter tool with no output schema, the description covers purpose, triggering contexts, session default and entitlement limits. The main gap is that it doesn't explain how the returned level values should be interpreted or their format, though annotations already relieve the safety burden.

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 parameters are documented by the schema itself. The description restates the session default but adds no syntax or meaning for dte_filter beyond what the schema provides, which is the correct baseline 3.

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 resource (dealer gamma-exposure key levels) and enumerates the outputs: gamma flip, max pain, call wall, put wall, spot. No sibling covers GEX levels, and the agent can tell exactly what comes back.

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 clear triggering contexts ('where price may pin, bounce, stall or accelerate') with a concrete example query. It lacks explicit when-not-to-use guidance (e.g., intraday vs. post-close, or how it differs from greek_exposure/volatility_term_structure), so it falls short of a 5.

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