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

Annotations already mark the tool as read-only and non-destructive, so the description adds useful behavioral context: the value is rarely changes, cacheable, and rate limited to 10 calls/minute with a 6-second minimum interval. This goes beyond the structured metadata without contradicting it.

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 short sentences, each earning its place: the first states the function, the second gives caching guidance, and the third documents the rate limit. No redundant or filler content.

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 zero-parameter, read-only getter, this description fully covers what the agent needs to know: what the version is for, that it can be cached, and the rate limit. No output schema exists, but the return value is simply described as a version string, which is sufficient for this tool's simplicity.

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 zero parameters and the schema coverage is 100%, so there is no parameter ambiguity. The description adds semantic context about what the returned string is used for, which is more than necessary for an empty-schema tool.

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?

States a specific verb and resource: get the contract signing version string. It also explains what the version is for (EIP-712 domain data when signing a withdrawal), making its purpose clear and distinct from sibling getters like get_config or get_withdrawal_status.

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?

Describes when the tool matters: it is required when signing a withdrawal, and it explicitly says the value rarely changes and is safe to cache client-side. It does not explicitly name alternatives or state when not to use it, but the context is clear enough for a no-parameter getter.

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