Describe the simulator

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

Annotations already declare readOnly, idempotent, closed-world, non-destructive, so the safety profile is covered. The description still adds real value: 'takes no arguments, runs no market and returns the same text on every call' confirms no side effects and deterministic output, which is more than the annotations alone convey. It stops short of noting response size or whether content is versioned, so not a 5.

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?

Front-loaded with the core purpose and the 'call it first' directive, which is the most decision-relevant sentence. The second sentence is a long comma-run enumeration of return contents that is dense but still scannable; it could be trimmed slightly without losing meaning.

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?

An output schema exists, so return-value explanation is technically optional, yet the description still summarizes the payload categories an agent needs to decide whether to call it. With zero params and full annotation coverage, nothing needed for correct invocation is missing.

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?

Zero parameters, so the baseline is 4. The description confirms this explicitly ('takes no arguments'), which is the only parameter-level information possible for an empty schema, but adds no further detail beyond that confirmation.

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 verb and resource (describe the simulator) and enumerates exactly what the response covers: realism checks, limitations, per-tool caps, run duration, presets, certified preset, background-trader populations, and market sessions. This clearly separates it from siblings like explain, list_scenarios, or check_envelope, which return data rather than self-description.

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 an explicit ordering rule: 'Call it first, before any other tool.' Combined with the note that it takes no arguments and runs no market, an agent knows precisely when this tool is appropriate versus any other sibling.

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