tokmeter_timeline

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

Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds value beyond that by describing what the output looks like (sparkline trends, daily cost/token breakdowns) in the absence of an output schema. It does not mention default window size or truncation behavior, but the schema documents those.

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?

Two sentences, zero waste. The core capability is front-loaded and the usage hint follows immediately; every clause contributes either purpose or selection guidance.

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?

With no output schema, the description's characterization of the return (sparklines, daily breakdowns) is the main signal an agent gets about output shape. Combined with fully documented parameters and safe-read annotations, the definition is sufficient, though it could note ordering or default scope behavior.

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%, with all four parameters including the scope enum fully documented in the schema. The description adds no syntax, default, or filtering detail beyond what the schema already provides, so baseline 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?

Specific verb and resource: 'Show a day-by-day timeline of token usage' plus the concrete payload ('sparkline trends and daily cost/token breakdowns'). It implicitly separates itself from aggregate siblings like tokmeter_pulse, but never names an alternative, so it stops short of full sibling differentiation.

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?

'Use this to see patterns over time — spending spikes, quiet days, and usage trends' gives a clear triggering context. There are no explicit exclusions or named alternatives, which matters here since tokmeter_heatmap and tokmeter_streaks also cover time-based patterns.

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