Top movers: OI spikes, extreme funding, widest basis, highest stress

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

With readOnlyHint and openWorldHint already supplied by annotations, the description adds valuable context by disclosing the output structure ('four top-10 lists in one call') and enumerating the exact metrics included. This is helpful beyond the annotations, though it stops short of detailing data freshness or list ordering.

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, directly front-loaded with a 'call when' trigger, and every word adds value. It avoids repeating schema or annotation information, making it highly efficient.

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 zero parameters, no output schema, and rich annotations, the description is sufficiently complete for an agent to invoke the tool correctly. It clearly communicates the high-level output (four top-10 lists) and categories; only minor details like field names or time window are absent, but these are not critical for selection.

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 accepts zero parameters, so the schema is trivially complete (100% coverage). The description reinforces that no input is needed, and it focuses entirely on output behavior, which is the appropriate use of description space for a no-parameter tool.

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 the tool returns top movers in crypto derivatives, listing specific categories (OI changes, funding, basis, stress). It distinguishes itself from siblings by explicitly aggregating four top-10 lists into one call, which is a unique multi-metric offering compared to single-metric tools like get_open_interest.

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 provides explicit when-to-use context: 'Call this when the user asks what is moving in crypto derivatives right now' followed by concrete query examples. It does not mention exclusions or alternatives, but the context is clear enough for an agent to route appropriately.

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