Search by image SHA-1

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, covering safety and side-effect expectations. The description adds the useful behavioral detail that no image upload occurs and requires an exact 40-character hash. It does not go deeper into rate limits, site behavior, or result handling, but given the strong annotation coverage, this is adequate.

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 a single, focused sentence that front-loads the core purpose and includes a meaningful qualifier ('without uploading the image'). Every word carries weight; there is 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 simple hash-lookup tool with two well-documented parameters, rich annotations, and an output schema, the description is sufficient. The only minor gap is that it does not explicitly address the exhentai site option or clarify how results differ between sites, but the schema and output schema cover the operational details.

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%, with clear descriptions for both parameters including the sha1 pattern and the site enum/default. The description restates the 'exact 40-character SHA-1 hash' concept already present in the schema, adding no substantial new semantic meaning. This meets the baseline for a fully schema-documented parameter set.

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 clearly states the action ('Search'), the target resource ('E-Hentai'), and the exact lookup key ('40-character SHA-1 image hash'). It also differentiates itself from file-upload search by emphasizing 'without uploading the image', which distinguishes it from sibling tools like eh_search_by_file.

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?

The description implies the proper usage context: use this tool when you already have an exact SHA-1 hash and do not need to upload an image. It does not explicitly name alternative tools or state when not to use it, but the 'without uploading the image' phrase provides meaningful contrast with file-upload-based search.

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