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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds behavioral context by specifying the return content (biography and works) and the flexibility of accepting an id or slug, which goes beyond the schema. This is valuable context that helps the agent predict the tool's output and input handling.

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 two sentences with no filler. The first sentence front-loads the core purpose and return content, and the second sentence clarifies the input format. Every word earns its place, and the structure is easy to parse quickly.

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?

Given the tool's simplicity (single parameter, read-only, no output schema), the description provides sufficient context. It explains what the tool returns (author, biography, works) and how to specify the input. The absence of error handling or pagination details is acceptable for a straightforward retrieval tool, especially since the annotations cover safety.

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 0% because the 'id' parameter lacks a description. The description compensates by clarifying that 'id' can be either an author ID or a slug. This is essential semantic information for correctly invoking the tool, and it is not present in the schema. Since there is only one parameter and the description adequately explains its meaning, this is a strong contribution.

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 returns an author, their biography, and the works held by Siftivo. This distinguishes it from sibling tools like get_book or get_series by specifying the resource type (author) and the specific data components. The verb 'get' is implicit in the name and title, but the description makes the scope explicit.

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 does not explicitly mention when to use this tool over alternatives or when not to use it. It only states the input format (id or slug), which is a parameter-level guideline. The intended use (retrieve author details) is implied but not contrasted with siblings like search_books or get_series.

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