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

Annotations already cover the safety profile (readOnly, non-destructive), so the bar is lower; the description adds genuinely useful context, notably the auth prerequisite ('Cotlet API key with access to this app') and a summary of what each report type contains. It omits pagination/return-format detail, but the auth disclosure is a real value add.

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?

Three tight sentences, front-loaded with the core purpose and then the report variants, with no filler. Slightly dense but every clause carries signal.

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 compensates by describing the content of each report return. Combined with the auth requirement and date-range defaults carried in the schema, an agent has nearly everything needed to call it correctly; only pagination/size expectations are unstated.

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 3 is the baseline, but the description goes beyond the schema by explaining what each enum value actually returns and clarifying that release_id applies only to revenue_summary. That is meaningful semantic enrichment of the report enum.

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?

States a specific verb (export) and resource (Bandcamp sales report) and enumerates the three report types with their contents. An agent can tell what it produces. It does not, however, explicitly differentiate itself from sibling read tools like bandcamp_list_sales, so it stops short of a 5.

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?

It explains what each report option returns and that release_id narrows revenue_summary, implying when each variant is appropriate. But there is no explicit when-to-use vs the bandcamp_list_sales sibling or any stated exclusion, leaving the routing guidance only implicit.

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