get_stats

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

Annotations already carry the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false, openWorldHint=true), so the description's burden is lower. It adds useful context by enumerating which aggregate figures are returned, but doesn't describe behavior beyond that. No contradiction with annotations.

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 with zero filler. The first sentence front-loads purpose and scope, the second adds usage guidance. 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?

For a zero-parameter aggregate tool, the description is complete. The output schema covers return values, annotations cover safety and idempotency, and the description covers scope and usage. Nothing an agent needs to invoke it correctly 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?

The tool has zero parameters, which sets a baseline of 4. The description adds value beyond the empty schema by explaining what the returned figures actually measure (totals, average rating, rating spread, films per year), giving the agent expectations about the output shape.

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 states a specific verb and resource ('Get archive-wide figures') and enumerates the concrete outputs (totals, average rating, rating spread, films per year). The 'archive-wide' scope clearly distinguishes it from per-film siblings like get_film, list_films, and search_films.

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 second sentence gives explicit when-to-use guidance: 'Use this for questions about the collection rather than one film.' This is a clear usage directive with an implied exclusion of per-film tools, though it doesn't name the alternative sibling explicitly.

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