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

Annotations are entirely absent, so the description carries the full burden of behavioral disclosure. It does disclose a usage limit ('5 free trial calls per registered wallet'), but it fails to state whether the operation is read-only, whether authentication or wallet registration is required, how errors surface, or what response shape to expect. The trial note is useful but far from sufficient.

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 very short, front-loads the core concept, and includes a concise, useful note about the free trial. The repetition of the tool name as a prefix is slightly redundant but harmless. It earns its place with minimal waste.

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 tool with two optional-looking parameters, no output schema, and no annotations, this description is too sparse to support correct invocation. It leaves unanswered what pair/symbol format should look like, whether either parameter is required, what time period or market the rate refers to, and what the return payload contains. The trial note is the only operational detail, leaving critical gaps for an agent.

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 schema descriptions 'Pair to process' and 'Symbol to process' are tautological and provide no format, relationship, or requiredness information. The tool description adds zero parameter context—no examples, no clarification of pair vs symbol, no guidance on which parameter to use. Despite 100% schema description coverage, the semantic value is near zero, and the description does not compensate.

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 identifies the resource as perpetual funding rates, which is a specific domain and distinguishes it from many unrelated siblings. However, it lacks a verb or explicit action such as fetch, get, or calculate, so the agent must infer that the tool returns or queries funding rate data. It does not clearly differentiate from other crypto market-data siblings like price or fear-greed tools beyond naming the metric.

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?

No guidance is provided on when to use this tool versus alternatives. There is no mention of pair/symbol selection, prerequisites, or what conditions make this tool the right choice. The only added context is a trial-call limit, which offers no decision support for tool selection.

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