list_expression_functions

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

With no annotations provided, the description must carry the behavioral disclosure burden. It states the tool lists functions, which implies a read-only operation, but it does not explicitly mention that it has no side effects, requires no authentication, or what the output looks like. This is a minor gap for a simple list tool, but the description is not misleading.

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 a single, concise sentence with no filler. It front-loads the core purpose (list functions) and includes the count, making it efficient and immediately scannable.

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 simple list tool with no params, no output schema, and no annotations, the description provides enough information for an agent to invoke it: it lists all built-in expression functions. While it lacks details about output format or sorting, the tool is trivial to call correctly. A slightly higher score is not warranted because the description doesn't describe the expected return shape.

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, and the schema coverage is 100% (empty schema). Per the rubric, a zero-parameter tool receives a baseline of 4. The description adds nothing about parameters because there are none, so the baseline stands.

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 action (list), the target resource (ELN expression engine built-in functions), and even specifies the count (22). This makes the tool's purpose unambiguous and distinguishes it from sibling list tools like list_components or list_templates, which target different resources.

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 no guidance on when to use this tool versus alternatives, nor any exclusions or prerequisites. While it's a specific list tool, the agent is given no explicit context about when it should be invoked (e.g., before modifying formulas).

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