evaluate

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

With no annotations, the description carries the full burden of behavioral disclosure. It only mentions 'strict grammar validation' as a trait, but does not disclose error behavior, state mutation (read vs. write), support for variables (despite sibling tools set_variable/get_variable), or return value format. This is a significant gap for a tool with no 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 a single, front-loaded sentence that communicates the core purpose and a key distinguishing feature. Every word contributes value; there is no repetition of the tool name or schema details.

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 tool with no annotations, no output schema, and two parameters, the description is too brief. It fails to mention how to reference variables (given sibling tools), what happens on invalid expressions (error vs. result), and what the return value of evaluation or validate_only mode looks like. This leaves significant gaps for a user or agent to use the tool correctly.

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?

Schema description coverage is 100%, as both parameters have descriptive text in the schema. The tool description itself adds no parameter-level semantics beyond what the schema already provides, so the baseline of 3 applies.

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 a specific verb ('Evaluate'), a resource ('mathematical expressions'), and adds a distinguishing scope ('strict grammar validation'). It clearly differentiates from the sibling tool 'validate_syntax', which likely only checks syntax without computing.

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 intended use (evaluating expressions) is implied by the tool name and description, and the validate_only parameter hints at a distinction from pure syntax validation. However, there is no explicit guidance on when to use this tool versus 'validate_syntax' or how it relates to the variable-related sibling tools.

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