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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so 'Read only' adds nothing. The genuinely useful addition is the auth requirement ('Needs the user's Cotlet API key with access to this app'), plus the fact the period aligns with Insights filters. It stops short of rate limits or failure modes.

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?

Purpose is front-loaded, but the description repeats itself: sentence one and sentence two both list 'total followers, RSVPs and ticket clicks,' and 'Read only' restates the annotation. There is noticeable redundancy for a two-parameter tool.

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 usefully describes the returned summary (metrics plus their deltas), covers the auth prerequisite, and confirms read-only behavior. For a simple 2-param stats tool it is close to complete, missing only sibling disambiguation.

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 both parameters (period enum, artist_id) are already documented, and baseline is 3. The description adds only that 'Periods match the Insights filters,' a small semantic link but no new syntax or default details beyond the schema.

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+resource (get follower stats) and enumerates the exact metrics returned: total followers, RSVPs and ticket clicks with change over a period, sourced from Insights. An agent can tell what it retrieves, but the description never differentiates it from nearby siblings like bandsintown_get_event_stats or bandsintown_get_top_markets.

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?

There is no when-to-use guidance, no exclusions, and no named alternative. 'Periods match the Insights filters' hints at context but does not tell the agent when this tool is preferable to the other Bandsintown stats tools.

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