validate_listing

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

Annotations already establish readOnlyHint, idempotentHint, non-destructive, and closed-world, so safety is covered. The description goes beyond that by enumerating exactly what is checked (character limits, keyword-field room lost to spaces, repeats, brand/filler words, locale language and script, uncovered tracked keywords) and restating "writes nothing" — genuinely useful since there is no output schema.

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, front-loaded with the core purpose before the long enumeration of checks. The middle list is dense and run-on, but every item is substantive and replaces a missing output schema, so nothing is wasted.

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 an 8-parameter, no-output-schema validation tool, the description supplies the otherwise-missing picture of what is returned by listing the checks performed, and clarifies the read-only contract. It does not describe output formatting or error behavior on malformed input, leaving a small gap.

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%, and each field (name, keywords, subtitle, description, promotionalText, locale, country) is already documented with limits and examples in the schema. The description adds only the optionality hint ("pass only the fields you want checked") and ties country to tracked-keyword coverage, so the schema does the heavy lifting — baseline 3 applies.

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+resource ("Check a draft App Store listing") with a clear pre-publish scope, which cleanly separates it from siblings like draft_listing, update_listing, and localize_listing that also touch listings but mutate or generate them. An agent can select this over those without opening any schema.

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 explicit timing context ("before it goes to App Store Connect") and an invocation rule ("pass only the fields you want checked"). It never names the draft/update siblings as alternatives or says when not to use it, so it stops short of full routing guidance.

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