subway_combos

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

No annotations are provided, so the description carries the full burden. It discloses what the tool returns (categories and prices), what it explicitly does not return (individual products, nutrition, allergens), that it is not an itemised menu, and the empty-array edge case. This is thorough and exceeds typical disclosure.

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?

The description is dense but every sentence adds value: it states the main function, contrasts with a sibling, clarifies scope and limitations, handles an edge case, and points to the source of the store_id. It is well-structured and front-loaded with the core purpose.

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 no output schema, the description explains the key return fields and the empty-array scenario. It covers the store_id source, the culture parameter (already in schema), and the difference from the menu endpoint. It does not fully specify the exact structure of the categories array, but it is sufficient for an agent to call the tool correctly.

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 both parameters (store_id and culture). The description adds a note about where store_id comes from, but this is also in the schema, and it does not provide new parameter-level meaning. Baseline of 3 is appropriate.

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 clearly states the tool fetches one Subway store's bundle/combo categories and specifies the exact output fields (min_bundled_price, a_la_carte_price). It explicitly contrasts with GET /subway/menu, distinguishing it from a likely sibling, making the purpose unambiguous.

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?

Provides explicit guidance: 'Unlike GET /subway/menu, which is US-only, this works in other markets' and 'Use GET /subway/menu for a full itemised menu where it is available.' It also explains that an empty categories array is a valid response, not an error, and indicates where store IDs originate.

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