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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior. The description adds useful topic semantics (topic0 is usually the keccak256 event-signature hash) but does not disclose operational details like pagination or return behavior, which annotations do not cover.

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 tight sentences: what the tool does, the key topic convention, and the required input condition. No filler, and the most important usage rule is front-loaded.

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?

Despite 13 parameters, the schema documents every parameter completely. The description provides the core selection/invocation insight (what topic0 means and that at least one filter is needed), which is enough for an agent to use the tool correctly alongside the schema and annotations.

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%, so the baseline is 3. The description adds value by explaining why topic0 matters (event-signature hash), how adjacent-topic operators combine filters, and the minimum filter requirement, going slightly beyond the schema's per-parameter wording.

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 the specific action 'Search event logs' with clear filters (contract address and/or topics) over a block range. This distinguishes it from sibling transaction/token tools without needing to open the schema.

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?

Gives clear usage context: event logs, block range, address/topic filters, and the explicit requirement to provide an address and/or at least one topic. It does not name alternative tools with exclusions, but no sibling directly competes for event logs, so the guidance is sufficient.

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