era_distribution_report

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

With no annotations provided, the description carries the behavioral disclosure burden. It discloses a concrete quota ('1 walk') and describes the output summary features ('percentages and peak-era callouts'). It does not explicitly state read-only behavior, but the report/histogram framing makes this reasonably clear.

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 tight sentences deliver the core purpose, both modes, bucket sizing, output highlights, and quota cost with no filler. The key behavior is front-loaded before the quota note.

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 covers mode semantics, bucket granularity, output features, and quota in a compact way. It is slightly incomplete in that 'walk' is unexplained and no alternative tool routing is given, but with no output schema it still gives enough for an agent to invoke the tool correctly in either mode.

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 coverage is 100%, so the baseline is 3. The description adds value by explaining how artist_id toggles modes and by defining bucket widths (5-year vs decade), which is not fully captured by the bare schema descriptions. Other parameters like saved_cap and include_groups are left to the schema, which is acceptable.

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 clearly states the tool produces a 'histogram of releases across eras' and distinguishes two modes: artist discography in 5-year buckets and saved-album library in decade buckets. It is specific about the resource and behavior, though it does not explicitly name or contrast sibling tools.

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 description gives explicit mode-selection guidance: pass artist_id for an artist discography, or omit it for the saved-album library. This is clear context for when to use each mode, but it does not state exclusions or point to alternative era/report tools, so it stops short of a 5.

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