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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the trailing 'Read-only' merely restates that, earning no credit. The description adds useful framing that this is a static rule set to consult prior to mutation, but says nothing about auth needs, caching/staleness, or rate limits beyond what annotations cover.

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, zero waste, and the payload contents are front-loaded before the usage instruction. The closing 'Read-only' is the only mildly redundant clause.

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 an output schema present, the description needn't enumerate return values in detail, and annotations already cover the safety profile for a zero-parameter call. Nothing an agent needs in order to invoke this 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 takes zero parameters, so the schema carries no semantics to add; baseline 4 applies. The description correctly implies a parameterless read that needs no input.

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?

Specific verb + resource ('Get the rules for App Store metadata') followed by an enumeration of exactly what is returned: editable fields, character limits, supported locales, and screenshot pixel sizes. This clearly distinguishes it from siblings like get_metadata, get_store_capabilities, and set_metadata.

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?

'Call it before set_metadata or upload_screenshots' gives an explicit precondition and names the two sibling tools it precedes, which is strong routing guidance. It stops short of stating when not to call it, so it isn't a full 5.

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