books_get_item

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

The input schema includes readOnlyHint and idempotentHint, which already convey that the operation is safe and idempotent. The description 'Get a specific item' is consistent with these annotations but provides no additional behavioral details such as error handling, response format, or whether the item is returned in full.

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?

A single, concise sentence of seven words that front-loads the action and resource. Every word earns its place, and there is no filler or repetition of schema details.

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 get-by-ID tool, the description is adequate but minimal. It doesn't specify what the response contains or how missing IDs are handled, which would be helpful given no output schema. The presence of readOnlyHint and idempotentHint reduces safety concerns, but the description could have added a bit more context about the returned item 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 0%, so the description must compensate. The phrase 'by ID' clarifies that item_id is the unique identifier, aligning with the parameter name. However, it doesn't elaborate on ID format or any constraints beyond the schema's type string, so the added meaning is minimal though present.

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 uses 'Get' as a specific verb and identifies the resource as 'a specific item from Books', with retrieval by ID. This clearly distinguishes from the sibling tool books_get_items, which would list all items. The action and scope are unambiguous.

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 usage when the caller has an item ID and needs a single item, but it doesn't explicitly mention alternatives like books_get_items for listing all items. The 'by ID' qualifier provides clear context, but there is no explicit when-not-to-use guidance or named alternatives.

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