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

Annotations already declare this a safe, idempotent, closed-world read, so the bar is lower, yet the description still adds substantive context: every row carries provenance, the collection is empty below a dataset threshold, and the data has third-party rather than first-party status. The plan-tier limitation (7 days on free) is disclosure an agent cannot get from annotations or schema.

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 identity of the data is front-loaded in the first sentence, followed by provenance, availability, presentation, and plan constraints. The telegraphic phrasing is dense but every clause carries a distinct operational fact; nothing is filler.

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 an 11-parameter filtered read with full schema coverage and no output schema, the description covers the things an agent could get wrong: source attribution, empty-state precondition, and plan limits. Return shape and pagination are handled by the schema's meta references, so the remaining gap is minor.

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% with 11 well-documented parameters including three enums, so the schema already carries parameter meaning. The description adds nothing about individual parameters, which is acceptable at this coverage level but keeps it at baseline.

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?

"Past lines supplied by third parties, not recorded by this API" states the resource and its scope precisely, and the negation clause separates it conceptually from tools returning this API's own observations (get_odds, get_line_history). It stops short of naming a specific sibling to prefer, so differentiation is conceptual rather than explicit.

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?

It supplies two real usage conditions: the dataset is empty until meta.available_datasets exceeds 0, and results must never be presented as lines this API observed. It also notes a free-plan restriction to the last 7 days. What is missing is routing guidance against alternatives such as get_line_history or compare_lines, so the agent must infer when this source is the right one.

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