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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower; the description still adds return-shape detail (public REST detail fields, publication-filtered relationships, page/media links) and the important not-found semantics where unpublished and unknown are indistinguishable. The closing sentence about book content and sample links is confusingly worded and only loosely tied to an author tool.

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?

Four short sentences, front-loaded with purpose and ID provenance, then return shape, then failure behavior. The final sentence about book content/sample links is tangential and vaguely phrased, slightly diluting an otherwise tight definition.

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?

There is no output schema, so the description usefully sketches what comes back (detail fields, filtered relationships, public links) and covers the not-found case. Given a single-parameter read tool with full annotation coverage, this is largely sufficient, with only the ambiguous closing clause as a loose end.

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%, so the description must carry the burden, and it does add provenance meaning beyond the raw pattern constraint: the id is a catalog ID sourced from search_authors or a related record. It does not describe the numeric format or length constraint, but the practical semantics are covered.

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 ('Retrieve one published author by its catalog ID'), scoping it to a single published author, which cleanly separates it from the sibling search_authors that returns many. The 'published' qualifier also signals the tool's boundary.

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?

Explicitly tells the agent where the required ID comes from ('obtained from search_authors or a related record'), which is the key routing decision, and states that unpublished and unknown IDs both return not found. It lacks an explicit 'do not use this to search' exclusion, but the usage context is clear.

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