List subscriptions and in-app purchases

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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered structurally. The description goes beyond that by disclosing the shape and scope of returned data, notably that price is shown in one territory while introductory offers are summarized across territories, which is genuinely useful behavioral context not present in the annotations.

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 verb and resource first, followed by a parenthetical enumeration of returned fields. No filler, no restatement of the title, 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?

With no output schema, the description must convey return contents, and it does so reasonably well by listing the fields returned. It is slightly incomplete on pagination/result-size behavior and on whether results span a single app or all visible apps, but nothing critical to invoking the tool is missing.

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 both parameters ('app' default resolution and 'territory' ISO code/default) are fully documented in the schema. The description's phrase 'price in one territory' loosely echoes the territory parameter but adds no format or default semantics beyond what the schema already provides, so the baseline of 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?

States a specific verb (lists) and resource (subscription groups, their subscriptions, plus one-time in-app purchases), and enumerates the returned fields, so the agent knows exactly what domain this covers. It does not name or differentiate from any sibling (e.g. remove_intro_offers or add_free_trial, which touch the same subscription objects), so it falls short of a 5.

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 when-to-use guidance, no prerequisites, and no mention of alternatives or when not to use it. Usage is only inferable from the verb 'Lists'. This matches the MID calibration where a read tool with no routing guidance scored 2.

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