Market Overview

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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds useful context about what metrics are included (VIX, put/call, GEX regime), which adds some value beyond the annotation. However, the 'Returns:' section is purely tautological ('Market-wide volatility and positioning overview') and restates the opening, missing an opportunity to disclose details like data frequency, index universe, or whether this triggers expensive computations. Adequate but not exemplary for a read operation.

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 well-structured with clear sections: a one-line purpose, a detail sentence, a 'Use this tool when' bulleted list, and a Returns line. It's front-loaded with the key purpose. Minor deduction for redundancy—the Returns line duplicates the opening sentence ('Market-wide...overview' vs 'aggregate volatility metrics'), and the use-when list could be more compact. Overall efficient at ~60 words with good scannability.

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 0-parameter, read-only, annotation-covered tool, this is well-completed. The description clearly positions it as the macro-level aggregate view among 42 siblings, and the metrics list (VIX, put/call, GEX) disambiguates from get_vix_snapshot and get_gex. The main gap is no mention of how real-time or lagging these metrics are, or typical latency—but given the tool's simplicity and no output schema expectations, this is satisfactory.

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?

With 0 parameters and 100% schema coverage (trivially), there is nothing for the description to explain. The baseline of 4 applies: the description correctly stays silent on parameters, and no additional semantics are needed. The tool takes no inputs, and the description doesn't invent any, which is consistent and clean.

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+resource+scope pattern: 'Get market-wide volatility overview' followed by concrete metrics (VIX levels, put/call ratios, GEX regime). The 'aggregate' and 'market-wide' framing distinguishes it from the many volatility siblings (get_vix_snapshot, get_gex) by positioning this as the broad umbrella tool. However, it stops short of explicitly naming sibling tools for when they'd be more appropriate, keeping it from a 5.

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 includes an explicit 'Use this tool when the user asks about:' section with four concrete triggers (Market overview, Overall market volatility, VIX and market sentiment, Broad market positioning). This gives clear context for an agent to route to this tool. However, it lacks any exclusion criteria or references to alternatives like get_vix_snapshot or get_gex, and some triggers ('Market overview') are tautological with the tool's name.

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