library_growth_timeline

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

With no annotations provided, the description carries the full behavioral transparency burden. It does state 'Read-only,' which clearly indicates no destructive or mutating side effects, but it does not mention potential costs such as paginating a large library, rate limits, or the effect of scan_cap on results. Adequate but not rich.

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 that opens with the action and resource, then lists concrete outputs after a colon. It includes the useful 'Read-only' safety note with no filler or redundant phrasing.

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?

The description names the key returned insights and the read-only nature, which is largely sufficient for a reporting tool with no output schema. It could add a bit more context about the scope of the scan or how it relates to library_growth_report, but nothing essential to invoking the tool is missing.

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 scan_cap, max_results, and response_format are already fully documented in the input schema. The description adds no extra parameter-level detail, matching the baseline of 3 when the schema handles the documentation.

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 uses a specific verb ('Show') and names the resource ('saved-track library') with concrete outputs: adds per month, busiest month, and monthly add streaks. It does not explicitly distinguish itself from the sibling library_growth_report, so it falls just 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?

No guidance is given for when to use this tool versus similar siblings like library_growth_report, listening_streaks, or saved_library_delta. The metrics list implies a reporting use case, but there are no trigger conditions, exclusions, or alternative routing.

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