List Catalog App Versions

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered by structured data. The description adds that matching is exact-key only and that results are node-scoped, but says nothing about result volume, whether the list is paginated in practice, or that the catalog must be synced (`sync_app_store`) for freshness — material context for an open-world lookup.

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 with the action, the identifying constraint, and the scope, with no filler or redundancy. The parenthetical examples aid recognition without bloating the definition.

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 only four parameters, one required, no output schema, and read-only annotations, the definition is close to sufficient but leaves gaps: an agent cannot learn from it whether results are paginated in a way that requires iteration, how versions are ordered (newest first?), or what identifying fields a version entry carries. These are inferable from the page/page_size schema properties, which keeps it at minimum-viable rather than inadequate.

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 coverage is 75%, with `app_key` and `nodeId` already documented in-schema, so the baseline of 3 applies. The description reinforces `app_key` as an exact key (its examples duplicate the schema's own examples) and ties `nodeId` to 'the selected node', but adds no meaning for `page` or `page_size` beyond what the schema declares.

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 names a specific verb and resource — 'List available catalog versions' — and constrains it to an exact App Store application key on a selected node, with concrete key examples (`openresty`, `mysql`, `halo`). It is genuinely distinguishable from mutation tools like `operate_installed_app`, though it never explicitly contrasts itself with the closest read sibling `get_app_update_versions`.

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?

Usage context is implied rather than stated: the word 'exact' signals that fuzzy or partial keys will not work, and 'on the selected node' signals that node scope matters. There is no explicit guidance on when to prefer this over `get_app_update_versions` or `list_installed_apps`, and no statement of prerequisites such as a synced store catalog.

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