market_snapshot

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

The annotations already declare readOnlyHint=true and openWorldHint=true, so the description doesn't need to re-state that it's a read-only operation. It adds a valuable source attribution ('Powered by Yahoo Finance') and lists the asset classes, which is useful context. However, it doesn't clarify what 'top crypto' or 'key ETFs' means, nor whether output includes real-time, delayed, or end-of-day data, which could matter for an agent picking a tool.

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 plus a source line: efficient, front-loaded with the core purpose, and no fluff. It misses a tiny opportunity to add 'use cases' without bloating, but as written it's tight.

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 zero-parameter, read-only overview tool with annotations covering the safety profile, the description is mostly complete. But given the sheer number of sibling snapshot/overview tools, a phrase like 'broader than futures_market_overview but narrower than egx_market_overview' would have made it much more complete for an agent deciding between siblings. Also, no output schema and no mention of return format, though that might be overkill for a snapshot tool.

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?

The tool has zero parameters, so there is nothing to document. The description's mention of asset classes (major indices, top crypto, FX rates, key ETFs) is the only semantic load-bearing content. With no parameters and 100% schema coverage meaning 'no params', the description does its minimal job but does not do more.

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 states a clear verb-noun phrase 'Global market overview' and lists covered asset classes (indices, crypto, FX, ETFs), which is specific enough to know roughly what the tool does. However, it does not distinguish itself from siblings like 'egx_market_overview' or 'futures_market_overview', so an agent might still pick the wrong macro tool. It's adequate but not great.

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?

There is no explicit guidance on when to use this tool versus alternatives. The description implies a broad use case, but with siblings like 'egx_market_overview' and 'futures_market_overview', the absence of any 'use this for X, not Y' direction is a gap. An agent has to infer from names alone.

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