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

Annotations already declare readOnlyHint and openWorldHint, yet the description adds real behavioral detail beyond them: omitting address_id triggers an additional default-location lookup. It also signals the nested 'tree' shape of the result, though it says nothing about ordering, size, or language effects on returned names.

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?

Two tight sentences with the core purpose and the collection-slug link front-loaded, followed by the optional-parameter tip. Dense but every clause carries information; no filler.

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?

For a read-only listing tool with full schema coverage and an output schema, this covers the essential gaps: what it returns conceptually, how it relates to the product-listing sibling, and the cost tradeoff on address_id. Minor omissions (empty-menu behavior, result ordering) are tolerable given the output schema.

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%, so country, city, store_id, language, and address_id are already documented in the schema. The description's address_id tip largely restates the schema's 'When omitted the store's own default location is looked up first', adding only marginal value, so the 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 uses a specific verb and resource ('List one Glovo store's menu collections ... as a tree') and explicitly names the sibling it feeds into ('the slug glovo_store_products takes as collection'), so an agent can distinguish it from glovo_store_products without opening either 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?

It establishes the workflow context (use this to obtain collection slugs for glovo_store_products) and gives concrete sourcing guidance ('Pass address_id from glovo_stores to skip an extra lookup'). It stops short of stating when-not to use it or what to do if the store has no collections.

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