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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe-read profile is covered. The description adds value by disclosing the return shape (publisher blurb, place fields), but says nothing about auth, rate limits, or pagination behavior beyond the annotated safety hints.

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 front-loaded sentence identifies the resource and id basis before enumerating fields. The long field list is informative but somewhat overlaps the output schema, keeping it just short of maximally tight.

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 and 100% schema coverage on all three parameters, the essential information for calling the tool is available. The description is complete enough, though its field enumeration partly duplicates what the output schema already conveys.

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%, with guide_id, lang, and country all documented in the schema, including the sources for the id. The description adds no syntax or format detail beyond that, so the 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?

The description gives a specific verb and resource ('One Apple Guide by id') and enumerates the returned content, making the retrieval intent unambiguous. It does not, however, name or differentiate itself from near siblings like apple_maps_guides_lookup or apple_maps_guides_publisher, so an agent must infer the distinction from the name alone.

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 explicit when-to-use guidance and no mention of alternatives or prerequisites. The phrase 'by id' implies a lookup, but the description never states when this should be chosen over the sibling guide tools (guides, guides_lookup, guides_nearby).

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