Apple App Store featuring

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

Annotations already cover read-only/open-world safety, and the description adds genuinely useful behavior: the nonexistent Android route returning an HTML 404, the ~1 MB per category-week payload size, and the date-range implication for cost. It does not disclose ordering guarantees beyond 'newest first' for scope=today or pagination behavior.

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 dense sentences, each carrying distinct information (mode semantics, platform limitation, payload size). Front-loaded on the scope distinction, though the opening reads as an enumeration of modes rather than a single crisp purpose statement.

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 10-parameter, no-output-schema tool, the description covers the highest-risk unknowns: platform support, mode semantics, and payload/date-range cost. The remaining parameters (limit, fields, format, dry_run) are self-documented in the schema, so nothing critical 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?

With 70% schema coverage the baseline is 3, and the description earns an extra point by explaining what scope=today vs scope=category actually return and the ordering, which is the key semantics behind the enum. It adds little on limit/fields/format, but those are already documented in 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?

The description states a specific resource ('Apple Today tab stories', 'apps featured in one category's sections') and separates the two modes the tool serves. It does not differentiate from the sibling sensortower_featured_history, which is the most likely confusion point, 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 gives a real usage constraint ('keep the date range short') and a hard limitation (iOS only, Android path 404s), which is more than pure implication. However it never says when to pick this over featured_history or how it relates to the top_charts siblings, leaving alternative selection to inference.

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