saved_track_age_report

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

No annotations exist, so the description carries the full burden, and the explicit 'Read-only' label is genuine behavioral disclosure. However, it doesn't disclose that scan_cap can truncate the paginated walk of the library (making the histogram possibly partial), nor any behavior around defaults or response_format differences.

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?

One sentence, zero filler. The core output concept and scope are front-loaded, the read-only trait is appended, and every word earns its place.

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 is the only place to define the result, yet it stops at 'age buckets plus a per-year add histogram' without defining bucket boundaries, explaining how scan_cap truncation affects the histogram, or how output varies by response_format. Invocable with defaults, but interpretation on large libraries is ambiguous.

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% — every parameter already has a documented meaning and default. The description's 'per-year add histogram' phrase describes output, not inputs, so it adds no parameter-level meaning beyond the schema; 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?

The description names a specific resource (liked/saved tracks) and field (added_at) and states the exact output shape: a histogram with age buckets plus a per-year breakdown. It is clear on its own terms, though it's phrased as a noun rather than a verb and doesn't explicitly distinguish itself from close siblings like saved_tracks_by_artist or added_on_this_day.

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 when-to-use or when-not-to-use guidance is given, and no alternatives are named. With roughly 200 siblings including several adjacent temporal/library reports (saved_tracks_by_artist, library_growth_timeline, added_on_this_day, taste_shift_report), the agent must infer applicability purely from the name and the histogram wording — no routing help is provided.

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