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

Annotations already declare read-only/idempotent, so the description wisely adds non-annotation context: the Pro key requirement, the fallback response (a count of versions) without a key, and the newest-first ordering. Missing details on rate limits or result shape beyond the top-level fields.

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 sentences, both dense and front-loaded: the return payload and ordering come first, then the use case and key prerequisite. No filler.

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 must carry the return contract; it does cover payload contents and ordering but omits how many results come back, what limit does, or how the fallback count is structured. Adequate but with clear gaps for a 2-param tool.

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 only 50% – slug is documented but limit (default 10, max 50) has no description in either place. The description never mentions result count, limiting, or pagination, so it fails to compensate for the coverage gap.

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 and resource: returns every captured version of an app's App Store listing, with contents (screenshots and preview videos per date) and ordering (newest first). It doesn't explicitly distinguish itself from siblings like get_screenshots or get_app_videos, so it falls 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?

Gives a concrete use case ("Shows how top apps change their creative over time") and a prerequisite (needs a Pro API key), plus the degraded behavior without one. It does not name alternative tools for related queries, so no explicit when-not guidance.

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