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

Annotations already cover read-only/idempotent/non-destructive safety, and the description adds genuine domain context beyond them: prices are ex-VAT with an inc-20%-VAT figure, and each dish carries menu price, ingredient cost per portion, food cost % and GP %. It doesn't mention data freshness or whether the starter menu is static, but the economic framing is substantive.

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-loaded with purpose, then the no-venue case, then the with-venue case, then the pricing caveat — a logical order. Slightly dense and re-enumerates the venue types already listed in the schema, which is minor redundancy.

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?

Despite an output schema existing, the description still conveys the shape and units of the return payload and the VAT convention, which is exactly what an agent needs to interpret results. With one optional enum param and full annotations, nothing material 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 enum already documents the four venue values, so the baseline would be 3. The description earns above baseline by explaining what each parameter mode actually yields (list of venue types vs per-dish cost breakdown), which the schema does not convey.

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 ('Get ChefSums's ready-costed starter menu for a UK venue type') and clearly distinguishes its two operating modes. It does not name or differentiate itself from siblings like calculate_gp or cost_recipe, so an agent can't tell from the description alone why it should pick this over those.

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?

Explicitly explains the two invocation modes: omit the venue to list venue types, supply a venue to get full dish economics. This is clear usage context, but there is no guidance on when this tool is preferable to the costing siblings (calculate_gp, cost_recipe), nor any exclusions.

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