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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so safety is covered. The description adds the content scope (biography + books + years, limited to Siftivo holdings), which aids selection, but says nothing about behavior for unknown authors, partial matches, or result size.

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?

Two sentences, zero waste: content and scope first, then the intents that select it. Every clause earns its place.

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?

With no output schema, the description usefully enumerates what comes back (biography, books, years), and the single-parameter surface is fully covered. Minor gaps remain around ambiguous-name resolution, but nothing needed to invoke it is missing.

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 100% and the description's id guidance ("author name, an author id, or a siftivo.com slug") is essentially identical to the schema description. Baseline 3 applies since the schema does the parameter work.

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 names a specific resource (author) and states exactly what is returned: a biography plus Siftivo's holdings for that author with years. It is clearly distinct from get_book/get_series by resource, though it never names a sibling to route against.

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?

It gives concrete user intents that select this tool – "what else has X written" and "tell me about X" – which is stronger than implied usage. It stops short of naming a when-not condition or an alternative tool for author lookups.

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