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

Annotations already establish that this is a read-only, non-destructive, non-open-world tool. The description adds useful behavioral context: it is paid, can use a direct credit, and returns a compact derived snapshot including alerts. It does not detail freshness, caching, or failure/payment behavior, so it is strong but not exhaustive.

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 and every sentence contributes useful information. However, it leads with pricing before the core purpose, so it is slightly less front-loaded than ideal.

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 simple one-parameter read-only tool with full schema coverage and no output schema, the description gives enough context to call it correctly. It explains the return gist, the paid nature, and when to use sibling tools instead.

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%, and the schema fully explains the single 'horse' parameter, including name formatting and the resolve_horse fallback. The description only reinforces 'one horse' and adds no parameter semantics beyond the schema, so the baseline of 3 applies.

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 states a specific verb and resource: 'Return a compact derived operating snapshot for one horse.' It also enumerates the snapshot contents and explicitly distinguishes itself from horse_intelligence, horse_explanation, and horse_changes.

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 a clear use case ('when you want a short current summary of one horse') and names the alternatives for full state, reasons, and historical changes. This lets an agent choose between sibling tools without opening their schemas.

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