update_app

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

Annotations only declare readOnlyHint=false, so the write nature is already known. The description adds meaningful behavior beyond that: attrs is 'merged onto the subscription' (not replaced), with typical shape { settings } and optional { status }, plus the side-effect note that update_app_review propagates shop_info. Missing auth/permission requirements keeps it from a 5.

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 sentences, front-loaded with the action, followed by the parameter contract and then the sibling routing. No filler; every clause carries information.

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?

For a two-parameter write tool with no output schema and only a minimal annotation, the description covers purpose, argument semantics, and sibling routing adequately. It leaves out permission/error behavior, which would be the only remaining gap.

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 100%, so baseline is 3, but the description adds semantics the schema cannot convey: that attrs is merged rather than replaced, and the conventional keys ('usually { settings: {...} }, optionally { status }'). That is genuine added value for a free-form additionalProperties object.

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 ('Update an installed app's configuration') and explicitly differentiates from the near-named sibling update_app_review. An agent can distinguish this from install_app/uninstall_app/update_app_review 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?

Gives an explicit routing rule: 'For the product-review app, prefer update_app_review.' That is a real when-to-use-this-vs-alternative statement. It does not, however, cover prerequisites or other cases (e.g. when to install vs update), so it is slightly short of full coverage.

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