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

Annotations already declare readOnly, idempotent, and no side effects, yet the description reinforces scale and behavior beyond the annotations: ~100 rows by default, dataset scoping, no pagination, no auth, and that prices/limits are absent. This adds real behavioral context, though it repeats the read-only/no-side-effects framing already in annotations, so not a full 5.

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?

Front-loads the core purpose and routing before detailing return fields. It is dense and every clause is useful, though the return-field enumeration is slightly lengthy; still efficient overall.

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?

No output schema exists, so the description carries the return-value burden and does so fully: it lists returned fields (id, name, vendor, dataset, checked, plans, page) and states what is absent (prices, limits). Combined with routing and scale info, an agent has everything needed to call it correctly.

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 enum is fully documented, so baseline is 3. The description goes beyond the schema by explaining the default behavior of omitting dataset (all products, ~100 rows) versus scoping to one, adding semantic meaning to the optional parameter.

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 ('Read-only list of the products (vendors) covered') and explicitly distinguishes purpose from siblings by naming get_tool and compare_tools as the id-lookup consumers. An agent can identify this as a catalog/ID-lookup tool without opening the schema.

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 explicit when-to-use ('to look up ids before calling get_tool or compare_tools') and when-not-to-use ('When the user already names a product, skip this and call get_tool or search_limits directly'). Both the positive and negative routing conditions are spelled out with named alternatives.

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