get_timeline_buckets

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

With no annotations provided, the description carries the full disclosure burden and meets it: it declares 'Read-only,' characterizes the call as cheap ('one cheap call'), and discloses ordering defaults ('newest month first unless order="asc"') plus per-filter counting semantics for every argument. This gives an agent a reliable safety, cost, and behavior picture that the empty schema and absent annotations do not provide.

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?

The description is front-loaded with a memorable summary, followed by a single purpose-driven usage sentence, then compact Args/Returns blocks. Given that the schema provides zero descriptions, every section earns its place, and the structured line layout keeps it scannable without bloat.

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?

Despite no annotations and an empty schema, an agent can select and invoke this tool correctly: all parameters are optional and documented, defaults are explicit, and the return shape (total_buckets plus buckets array of {timeBucket, count}) is stated even though an output schema exists. The only minor omission, the concrete type of timeBucket, is covered by the output schema.

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 tool description must carry all parameter meaning, and it does: a documented Args block explains all five parameters (album_id, person_id, tag_id, is_favorite, order), including what each filter counts and the order value/default. This fully compensates for the empty schema.

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 opens with a specific resource and behavior: 'Month-by-month map of the library: one bucket per month with its asset count,' which clearly defines an aggregation tool over time buckets. It implicitly distinguishes itself from the sibling get_timeline_bucket (singular) by describing a full month-by-month map, and frames its role as a pre-fetch navigation aid rather than a per-item lookup.

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?

'Use this before fetching assets' gives an explicit point-in-workflow trigger, and the description names concrete use cases: 'finding gaps, busy periods, or navigating a large library without paging through everything.' It does not name specific alternative tools or state when not to use it, so it stops just short of full exclusion guidance.

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