list_tools

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

Beyond annotations (readOnlyHint, openWorldHint), the description adds valuable behavioral context: 'read live from the gateway so it is always current' and 'Free — no payment'. It also clarifies that tools with priceMicroUsd 0 are free and need no wallet. This enriches the agent's understanding without contradicting annotations.

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 three sentences, each earning its place. The first front-loads the core purpose and content, the second confirms free usage, and the third provides additional pricing guidance. No wasted words, well-structured.

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 the low complexity (no parameters) and presence of an output schema, the description covers all necessary context: what is listed, that it is live, free, and provides usage guidance. It also names the sibling 'tool' as the next step, making the tool's role clear.

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 the schema fully covers them (100% coverage). The description adds no parameter-specific details but does clarify the output fields (name, HTTP method, etc.), which is indirectly useful. Per rubric, 0 params baseline is 4.

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 exactly what the tool does: 'List every GlianaAI utility tool (name, HTTP method, per-call price, an example input, and usage guidance)'. It uses a specific verb (List) and resource (utility tools), and details the contents. It clearly distinguishes from siblings like list_models or get_schema.

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 explicitly instructs when to use: 'Call this before `tool` to pick one and learn its input shape.' It also provides context about free usage and pricing, giving clear guidance. While it doesn't list exclusions, the instruction is direct and sufficient.

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