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

Annotations already mark this as read-only and non-destructive. The description adds valuable behavioral details beyond annotations: the 2000-line cap, the byte-range request ensuring the whole object is never loaded, and the lineCountCapped flag in responses. It also includes a security note to treat content as data, not instructions. This substantially enriches the agent's understanding of how the tool behaves.

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 well-structured, leading with the core behavior and cap, then the endpoint, then auth instructions, and a closing security note. It's fairly concise and front-loads the most critical information. The final note about ChangeRequests feels slightly tangential for a read-only tool, but it doesn't bloat the description significantly.

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 read-only tool with rich annotations and schema, the description covers the essential operational details: the line range cap, byte-range efficiency, auth requirements, and a safety note. It lacks an explicit description of the response format (though output schema is absent, so that's expected) and error handling, but for a simple line-range read it's sufficiently complete 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?

Schema coverage is 75% (three of four parameters have descriptions). The description reinforces the inclusive 1-indexed semantics and the 2000-line cap, but this information already exists in the schema descriptions. It adds the HTTP endpoint and the need for targetSpaceId in multi-space scenarios, but that's also in the parameter description. With high schema coverage, the description doesn't need to add much, and it does add marginal value, but not enough to elevate above baseline.

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 tool reads an exact line range from an asset's text, using a byte-range request. It distinguishes itself from broader read tools like assets_get or assets_download by emphasizing the specific line-range capability and the server's efficient byte-range loading. However, it doesn't explicitly name a sibling alternative, so a perfect score isn't warranted.

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 provides some usage context: it mentions the need to call auth_verify and ask the user which space to use for multi-space accounts, and it explains the HTTP endpoint. However, it doesn't explicitly state when to use this tool over other read options (e.g., nodes_read_lines or assets_download), nor does it give conditions for not using it. The guidance is implicit rather than explicit.

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