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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds only that it 'safely parses' and returns x/y points, which is useful but does not disclose domain sampling behavior, error handling, or other operational traits.

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?

It is a single front-loaded sentence with no filler. However, 'Safely' is vague and the brevity comes at the cost of routing context, so it is concise but not maximally 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?

Output schema exists and parameter schema is fully documented, so return values and inputs do not need explanation in the description. The main remaining gap is selection context: with many calculator siblings, especially calculator_function_plot, the description does not explain when this tool is preferred.

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%, so the schema already documents equation, variable, x_min, x_max, and num_points. The description adds no parameter detail beyond the y=f(x) shape already present in the schema, so the baseline 3 is appropriate.

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 and resource: parse y=f(x) and return x/y points for graphing. It is clear what the tool does overall, but it does not differentiate from the very similar sibling calculator_function_plot, so it stops short of a 5.

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 phrase 'for graphing' implies a general use case, but there is no explicit when-to-use guidance, no exclusions, and no alternative such as calculator_function_plot named. It leaves the agent to infer selection from the name and description alone.

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