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

Annotations already declare readOnlyHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds non-obvious behavior the annotations cannot: a hard 250-item cap and what to do when truncation occurs. It stops short of stating ordering or whether images/options are included, which keeps it at 4 rather than 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?

Three sentences, front-loaded with the core action, then usage, then the limit and its workaround. No sentence is redundant and the truncation caveat is placed where an agent will read it before calling.

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 values need not be re-explained, annotations carry the safety profile, and the description closes the one real gap — the 250-item cap and its fallback. Everything an agent needs to call this correctly and handle a truncated response is present.

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 100%, with merchantId and the language enum both documented in-schema, so the baseline is 3. The description implies the merchant scoping but adds no syntax or format guidance for either parameter 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 ('Fetch the entire menu of a merchant') plus the scope ('all categories and all items'), which distinguishes it from the paged/search siblings by contrast. The name-plus-description pair leaves no ambiguity about what is returned.

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 an explicit when-to-use ('user wants to browse the full menu', 'find an item across all sections without paging') and an explicit fallback when the result is truncated: search_merchant_products with a query. Both the positive and the escape-hatch path are named.

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