list_report_files

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), so the bar is lower. The description adds a genuinely useful operational constraint beyond that: the report bucket must be pre-configured and must not be guessed, which prevents failed calls.

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 short, zero-waste sentences: purpose first, then the two value domains, then the hard precondition. Every sentence carries information an agent needs and nothing is padded.

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?

An output schema exists, so return values need not be explained, and the annotation set is rich. Still, the pagination parameter (page_token) and its behavior are unaddressed, and the relationship to the sibling read_report is left implicit for a tool whose whole job is to feed that next step.

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 0%, so the description must compensate, and it partially does: it enumerates family values ('installs, ratings or store_performance') and the month format ('YYYYMM'). It says nothing about the 'package' parameter's expected form or the 'page_token' pagination parameter, leaving half the inputs undocumented in both places.

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 monthly Play CSVs for an allowed app', with the scoping domain (Play reports) made explicit. It never names or contrasts itself with siblings such as read_report (which presumably fetches CSV contents), so an agent must infer the boundary from the verb alone.

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 a precondition ('Exact report bucket must be configured; no bucket-name guessing'), which steers correct invocation. However, there is no explicit when-to-use vs. when-to-use-alternative guidance, and no statement of how this differs from read_report in a workflow.

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