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

Annotations already provide readOnlyHint=true. The description adds useful behavioral context: it returns current snapshots, callers may store them for their own analysis, and it is explicitly not a historical archive. It does not detail rate limits or update cadence, but the bar is lowered by the read-only annotation.

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 sentences, front-loaded with the primary purpose and scope. The use-case phrase and the non-archive clarification are both informative and earned; there is no 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?

With no output schema, the description partially compensates by referring to get_live_odds for shape, which is a sibling the agent can inspect. It covers currentness, sport-scoping, and snapshot storage, but does not state response fields or refresh behavior on its own.

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%, so the parameters are already fully documented. The description adds no parameter-specific meaning beyond the schema, making the baseline 3 appropriate.

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 names a specific verb and resource: it returns current prematch Pinnacle odds for one sport. It also distinguishes itself from live odds by saying 'prematch' and from a historical archive by explicitly stating 'this is not a historical opening/closing-odds archive.'

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 gives clear context on when to use the tool: for current prematch odds, handicapping, EV screens, and model features. It states an exclusion ('not a historical opening/closing-odds archive'), though it does not explicitly name alternatives like get_live_odds or get_prematch_lines.

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