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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds genuinely new behavior: no authentication required, and the no-query fallback returning the newest products, which is not derivable from the annotations or schema.

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 the core verb and scope, then return fields, fallback behavior, and auth. The 'same as search_products' clause is arguably redundant since a sibling of that name already exists.

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?

An output schema exists, so return-value explanation is not strictly required, yet the description still names the key fields. Combined with auth requirements, empty-query behavior, and the id-to-product_id linkage, an agent has enough to call it correctly; only the limit parameter is left unaddressed.

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 only 50% (the query param is described, limit is not). The description compensates partially by explaining the empty-query case and the keyword nature of the search, but says nothing about the limit parameter's default or the 1–20 cap, so it neither fully compensates nor adds much beyond the schema.

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: 'Search the product catalog ... by keyword'. It also names the sibling relationship ('same as search_products'), which tells the agent what the tool is but not how it differs, so it stops short of full sibling differentiation.

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?

Gives real usage context — 'Without a query: the newest products' and 'No sign-in needed' — which tells the agent what happens with an empty call. However, saying it is 'same as search_products' without saying when to prefer one over the other leaves the choice ambiguous rather than resolved.

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