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

With no annotations provided, the description bears the full burden of disclosing behavior. It fails to state whether the tool is read-only, what 'machine-readable evidence' means, what the output format is, or any limitations. The tool could be a read operation, a subscription, or anything else – the description leaves this entirely unknown.

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 extremely short, but this is not conciseness – it is under-specification. It lacks essential information and provides no structure or front-loading of scoping constraints. While it is one sentence, it does not earn its place because it conveys almost nothing useful.

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?

Given a completely open schema with no defined parameters, no output schema, and no annotations, the description must provide all context. It fails to explain what the tool does, what inputs it accepts (even though open, it could accept filters), what it returns, or any constraints. This is wholly inadequate for an agent to call it correctly.

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?

The tool has 0 parameters, so the baseline is 4 per the rubric. The schema is empty (with additionalProperties: true), and the description adds nothing about inputs, but since there are none, this is acceptable. The description does not mislead about parameters.

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 'Return Australian horse racing intelligence from Horse Truth machine-readable evidence' is essentially a tautology that restates the tool name without specifying what intelligence, what actions are available, or how it differs from sibling tools. It gives no concrete verb or resource beyond 'return' and 'intelligence,' which is not informative for an agent deciding when to call 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 guidance on when to use this tool versus alternatives. No context about situations where this tool is appropriate, no mention of exclusions, and no reference to sibling tools. An agent would have no basis to select this over other tools like 'tiktok_trends' or 'linkedin_jobs'.

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