plot_timeseries

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

The description discloses the return format ('JSON + inline PNG'), which is a useful behavioral trait. However, with no annotations, it omits other details such as handling of missing values, aggregation behavior, or whether it is read-only, leaving the agent to assume based on the tool type.

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 extremely concise with two short phrases that are front-loaded with the core purpose. It avoids unnecessary fluff, though it might be too sparse for a tool with five parameters.

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 there are five parameters and no annotations or output schema, the description is inadequate. It fails to explain what each parameter does, what constitutes valid inputs, or what the returned JSON+PNG structure looks like, making it incomplete for reliable invocation.

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 0%, and the tool description does not explain any parameter. Parameter names (source_id, time_column, value_columns, agg, granularity) carry some self-descriptive weight, but the description adds no specific meaning or usage examples, so it provides little value beyond the raw schema.

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 'Line plot over time' clearly identifies the tool's function as creating a time-series line plot. This distinguishes it from other plot siblings like plot_scatter or plot_boxplot, though it could be more explicit about what data it operates on.

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?

No guidance is given regarding when to use this tool versus other plot tools, such as plot_distribution or plot_scatter. The usage context must be inferred entirely from the name and minimal description.

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