getGlobal

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

Description states it is read-only, takes no parameters, and needs no API key. This is sufficient given the tool's simplicity, but no additional behavioral details like rate limits are provided.

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?

Two concise sentences front-load the purpose, usage guidelines, and key constraints. No unnecessary information.

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?

Covers the tool's purpose and use cases well, but does not describe the output format (e.g., JSON structure). However, given no output schema, this is a minor gap.

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?

No parameters exist, so baseline 4 is appropriate. Description adds no parameter info, which is fine as schema coverage is 100% with zero parameters.

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?

Description clearly states it provides a global crypto market overview including total market cap, volume, Bitcoin dominance, and market-wide change. It distinguishes from siblings like getTickersById for single coin prices.

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?

Explicitly tells when to use (e.g., 'how is the crypto market doing') and when not to (use getTickersById for single coin). Also mentions read-only and no API key required.

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