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

Annotations already establish readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description earns credit by disclosing that the payload is priced and category-grouped and that it spans three different catalog types (restaurant/grocery/shopping store), which is non-obvious behavioral context beyond the annotations.

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 front-loaded sentence that packs the resource type, contents (prices, category grouping), and the keying inputs without a wasted clause.

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?

With an output schema present, return values need no explanation, and both inputs are fully documented in the schema. The description adequately covers what the tool yields and its scope across catalog types, leaving only the pre-requisite search step implicit.

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%, and both uname and market are already documented with their allowed market values in the schema. The description adds only the phrase 'by uname and national market', which repeats rather than extends the schema. Baseline 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 names the resource precisely and distinguishes scope: it returns a restaurant menu, grocery aisle, or shopping-store catalog with prices grouped into categories, keyed by uname and market. That is clearly distinct from deliveroo_search (which finds slugs) and deliveroo_restaurant (which gives establishment detail), though it never names those siblings explicitly.

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?

Usage is only implied: 'by uname and national market' hints that a slug from a prior search is required, and the schema confirms the uname originates from a search response. There is no explicit 'call deliveroo_search first' instruction nor any when-not guidance versus deliveroo_restaurant.

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