what_changed_between

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

No annotations provided, so description carries full burden. It mentions it's a client-side composition of two snapshots and that it's cheaper when only IDs and names are needed, but doesn't detail rate limits, permissions, or exact output structure.

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?

Description is concise—3-4 sentences—all sentences are informative: purpose, examples, efficiency note. No redundancy.

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?

Given no output schema, the description adequately explains what is returned (appeared/disappeared entities, persistent IDs) and optional filters. It could be more precise about the response shape but covers the main aspects.

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%, so baseline is 3. The description adds context about optional filters and usage examples but does not provide significant new details beyond the schema descriptions.

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 computes a diff between two years, returning entities that appeared, disappeared, and persistent IDs. It explicitly distinguishes from a sibling tool (snapshot_at_year) by noting it's a client-side composition cheaper than two snapshot calls.

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 provides concrete example queries and notes when the tool is more economical than calling two snapshots. It lacks explicit 'when not to use' guidance but the context is clear.

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