history

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

No annotations provided, so the description carries full burden. It discloses return format (series with fields for posts and profiles), ordering, and behavior for unfetched URLs (empty series). It does not mention authentication or side effects, but it's a read-only 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?

Three succinct sentences: first states purpose and return, second explains 'since' parameter, third explains empty series case. Each sentence adds value, and the most important information is front-loaded.

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 tool with 2 parameters and no output schema, the description explains the return format, the 'since' parameter usage, and the empty series behavior. This is sufficient for an agent to use the tool correctly without additional documentation.

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%, but the description adds meaning beyond: explains the 'since' parameter for delta polling, and hints at return fields. The URL parameter is described as public post or profile URL. This provides useful context for correct usage.

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 clearly states the tool gets the recorded metrics history of a post or profile, the growth curve, and specifies the return format (series of snapshots) and ordering (oldest first). It distinguishes from siblings by focusing on history vs. current metrics.

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?

The description explicitly tells when to use this tool: to get history, and when to use alternatives: call metrics or profile if the series is empty. It also explains the 'since' parameter to poll delta, avoiding fetching the whole series.

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