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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuine value beyond that: it discloses the returned shape (normalized listing summaries with name, brand, price, image, availability) and notes pagination via the upstream page count, which is not derivable from the annotations alone.

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 dense sentence that front-loads the browse action and filtering rule before the return summary. No filler, but the parenthetical-heavy construction is slightly harder to parse than it needs to be.

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 and 100% parameter coverage, the description needn't restate return fields, but it does summarize them and captures the critical at-least-one filter precondition. It is essentially complete for correct invocation, with only minor gaps around slug sourcing.

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 baseline is 3, but the description adds a real constraint not encoded in the schema: only gender is marked required, yet the description states at least one of designer/category must be supplied. It also clarifies the department/filter relationship, giving more meaning than the schema alone.

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 (browse) and resource (Farfetch's luxury multi-brand marketplace) plus the exact filtering axes (department plus designer/category). This clearly distinguishes it from siblings like farfetch_product, farfetch_categories and farfetch_designers, which serve different lookup roles.

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?

The description states the filtering rule ('a designer and/or category filter (at least one required)'), which tells the agent when the tool is applicable and what must be supplied. It does not explicitly name the sibling endpoints used to obtain slugs, though the schema descriptions do reference GET /farfetch/categories and GET /farfetch/designers.

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