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

With no annotations, the description carries the burden and discloses the important behavior: it returns a page excerpt plus attached documents, an empty attachment list means no document is on file, and a missing product yields a plain statement with nearest-name suggestions. It does not mention permissions, rate limits, or explicit read-only status, but for a lookup tool the disclosed return and failure semantics are substantial.

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 purpose is front-loaded in the first clause, and every sentence contributes useful guidance. The middle sentence is somewhat long and clause-heavy ('Those attachments are the authoritative answer to...'), which slightly reduces scannability, but there is no filler.

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 a one-parameter lookup with no output schema and no annotations, the description is complete: it explains what is returned, how to interpret empty attachments, and what happens when the product does not exist. Nothing an agent needs in order to call it correctly 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 single 'name' parameter is fully documented in the schema, including case-insensitive matching. The description reinforces that the name must be the one returned by list_products, but adds little syntax or format detail beyond the schema, so the baseline of 3 is appropriate.

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 states a specific verb and resource ('Look up one product by name') and explicitly ties it to the sibling tool that produces the input ('as returned by list_products'). It also enumerates what comes back (excerpt, attached documents), making it easy to distinguish from list_products and search.

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 specifies when to use it (looking up one known product by name from list_products) and gives an explicit when-not: do not search separately for documents, because an empty attachment list is authoritative and searching 'will only turn up a different product's manual.' It also tells the agent how to interpret a missing product, which is a usage decision point.

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