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

Annotations already declare readOnlyHint and openWorldHint, covering the safety profile. The description adds value by disclosing what the response contains (profile, covered cities, guides) and that city scoping is optional, but it says nothing about pagination, auth, or rate limits. Solid addition beyond annotations without being rich.

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 tight sentences, front-loaded with the core verb and resource, followed by the routing hint. Every clause earns its place with 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 an output schema present, the description needn't explain return values, and 100% schema coverage documents the parameters. The description is complete enough for correct invocation; only marginal behavioral detail (pagination, error conditions) is absent.

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 the schema already documents publisher_id, city_id, lang, and country. The description only restates the city scoping and the publisher_id basis, adding no syntax or format detail beyond the schema. Baseline 3 is correct.

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 ('Fetch') and a well-scoped resource ('one Apple Guides publisher's profile, covered cities, and guides by publisher ID'), plus the optional city scoping. It names the sibling tools it is not, so an agent can distinguish it from apple_maps_guides and apple_maps_guides_publishers without opening schemas.

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?

Explicitly routes the agent: use apple_maps_guides_publishers to find publisher IDs, or apple_maps_guides_lookup to search by guide name. The condition selecting each alternative is stated, leaving nothing to inference.

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