List screenshots

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds genuinely useful behavioral context not in the annotations: results come back in display order with 1-based positions, plus file names, sizes, states and IDs. This is valuable since there is no output schema, though it says nothing about pagination or result-size limits.

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?

A single well-formed sentence that front-loads the verb and resource, then appends the returned field list. Every clause earns its place; the trailing enumeration is dense but directly useful given the absence of an output schema.

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 read-only list tool whose annotations carry the full safety profile and whose schema is fully documented with defaults, the description is nearly complete: it conveys the scope, grouping, ordering and returned fields. The only gap is the lack of any usage routing or result-volume context, which is minor here.

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 all five parameters (app, locale, version, platform, display_type) are already documented with defaults and enum values. The description only echoes that results are grouped per localization and display type, adding no syntax or format detail beyond the schema. Baseline 3 applies when the schema does the heavy lifting.

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 (Lists) and resource (App Store screenshots) with scope (for a version, per localization and display type), and enumerates the returned fields. It is clearly a read operation, distinguishable from siblings like replace_screenshot, reorder_screenshots and delete_screenshots, though it never names them explicitly.

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 prerequisites, and no mention of alternatives. The only implied usage is that this is the read step before mutating screenshot tools such as reorder_screenshots, which the agent must infer on its own.

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