get_time_series

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

Annotations already carry the safety profile (readOnlyHint, openWorldHint, idempotentHint), lowering the bar, and the description adds behavior beyond them: the 0-100 value cap, the conditional 'plus volume when available', and a failure-mode instruction that on rate limiting or quota exhaustion the agent must tell the user their plan limit is reached. No contradiction with the readOnlyHint. One minor gap: 'volume' is never defined, though this is not material to invoking the tool.

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?

Four sentences, each earning its place: core definition, primary use case, two sibling exclusions with routing, and one failure-mode instruction. The core scope constraint is front-loaded ahead of the routing and error-handling guidance; zero waste.

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 no description-level coverage; annotations cover the safety profile; the schema covers parameters at 100%. The description covers when to use it, when not to, which siblings to prefer, and how to handle quota/rate-limit failures. Nothing an agent needs to call it correctly 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% — the schema already enumerates all valid sources and gives per-source keyword format rules (npm case-sensitivity, Android bundle IDs, Steam naming). Baseline 3 applies. The description's 'one keyword and one source' merely reinforces the schema's 'Exactly one source per request' without adding net-new parameter meaning.

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+resource: returns the full historical series for exactly one keyword and one source, quantified as '0-100 values, plus volume when available'. The one-keyword/one-source scope distinguises it from broader or aggregated tools, and it explicitly names both siblings (get_top_trends, get_growth) as things it is not.

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 positive use case ('Use for charting or custom math'), an explicit exclusion with a named alternative ('Not for live what's trending now boards (use get_top_trends)'), and a routing rule ('For most growth questions, use get_growth'). An agent knows exactly when to pick this tool over either sibling.

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