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

Annotations already declare readOnly, idempotent, openWorld, non-destructive, but the description adds real behavioral context beyond them: metered usage and account-dependent access/delay, a single bounded request with no polling or auto-retry, affiliate 27 exclusion, and the caveat that an empty result does not prove lack of coverage.

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 purpose is front-loaded, but the body is a run-on sequence of policy fragments ('Read-only Product data or price calculation', 'Access, delay and metered usage...') that mixes purpose, safety, and caveats without clear structure. It is compact but not cleanly organized.

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. However, for a nested 2-parameter tool with 0% schema description coverage and many near-identical siblings, the description omits parameter meaning and sibling differentiation, so an agent still lacks enough to invoke it confidently.

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 schema documents only types and patterns for eventId, lineId, and the 'include' enum. The description never explains what lineId is, how it differs from eventId, or what the include=all_periods option returns; 'Use returned canonical IDs' is the only faint hint and is not tied to a named parameter.

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 opening phrase 'Get event by line ID' states a verb and resource, but it is essentially a restatement of the title and name rather than a richer explanation. It does not distinguish this tool from close siblings like v1GetEventByID or v2GetEventByID, leaving the agent to guess which lookup key (line ID vs event ID) selects it.

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?

There is no explicit when-to-use or when-not-to-use guidance, and no alternative tool is named despite a dense sibling set (v1GetEventByID, get_main_lines, v1GetMoneylines). 'Use returned canonical IDs' hints at a workflow but does not tell the agent when this tool is the right call versus a sibling.

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