List subscriptions

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description still adds real value: newest-first ordering, the {total, data} response envelope, and that secrets are returned masked via secretHint — none of which the annotations convey.

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?

Three tight sentences: scope and ordering first, paging/masking second, routing guidance last. No filler, and the most decision-relevant facts are front-loaded.

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?

No output schema exists, so the description supplies the return shape and ordering an agent needs to parse results, plus the secretHint masking caveat. Combined with the fully documented schema, nothing material is missing for a read-only list call.

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 every filter (date, status, carrier, flightNumber) and the paging params are already documented in detail. The description only restates that filters are optional and paging uses limit/offset, adding no format or behavior detail beyond the schema. Baseline 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?

States a specific verb and resource ('List the subscriptions owned by this API key'), plus ordering (newest first) and return envelope {total, data}. The closing sentence names the downstream siblings (get, update, pause, resume, delete, log calls), so an agent can separate this from get_subscription or list_deliveries without opening a 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?

Explicitly frames the tool as the id-discovery step before get/update/pause/resume/delete/log calls, and notes that all filters are optional with limit/offset paging. It doesn't state when-not to use it or contrast with search_flights, but the primary use case and alternative path are clear.

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