parlayapi_set_bettable_books

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

With no annotations, the description carries the full burden and does disclose the core behavior: the tool persists user book preferences and affects future parlayapi_verdict recommendations. It also documents the precedence rule that books overrides region. It does not discuss response behavior, errors, or how repeated calls should be handled, but the main side effects are covered.

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 description is compact, with no filler. The core purpose and trigger come first, and the Args section adds critical parameter details without unnecessary context. Every sentence contributes to correct invocation.

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 two-optional-parameter configuration tool, the description covers when to call, what to pass, how parameters interact, and why it matters. It is slightly ambiguous about what happens on a second call or if neither parameter is provided, but for a single-call setter this is not a major gap.

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 description must compensate and does: it lists region's allowed values (us | eu | uk | au | ca) and explains books as an exact CSV with an example. It also clarifies the relationship between the two parameters with 'Overrides region.' This adds genuine meaning beyond the bare schema.

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 uses a specific verb and resource: 'Remember which books the user can bet at' and explains the downstream effect on parlayapi_verdict. This clearly separates it from all sibling tools, which are data/retrieval operations rather than a user-context setter.

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 gives a concrete trigger: 'Call this once when a user tells you where they bet', with an example. It also says parlayapi_verdict will automatically use this setting so region/books do not need to be passed every call. It does not explicitly mention when not to call or how to handle updates, but the context is clear.

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