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

The description goes well beyond the annotations by explaining the exact return structure (mdp_url, plp_subscribe_url, plp_leasing_url), the URL path patterns, the behavior when 'model' is omitted, and the notion of 'currently available models.' This adds substantial behavioral context not present in the read-only/idempotent/not-destructive hints.

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?

The description is well-structured and front-loaded with the core purpose. Each sentence adds necessary detail—URL types, usage guidance, and fallback behavior—with no redundancy or fluff.

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 no output schema, the description fully explains what the tool returns (three URL fields with patterns) and the effect of omitting model. It also provides context for when to use each URL type, making it complete for correct invocation.

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% with clear descriptions for both brand and model. The description reinforces the optionality of model and provides concrete examples (e.g., 'Ford', 'Puma') and explains how parameters map to the returned URLs, adding value beyond the schema without introducing new constraints.

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 states a specific action ('Get canonical FINN URLs') and a clear resource ('for a brand and its models'), with the purpose of building internal linking blocks on SEO pages. This clearly distinguishes it from sibling tools like get_available_filters or search_vehicles, which handle different concerns.

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 provides explicit guidance on when to use each URL type ('Use plp_leasing_url when linking from a Leasing advisory, plp_subscribe_url when linking from subscription content') and mentions the intended use case. It does not explicitly exclude sibling tools, but no direct alternative exists for URL generation, so the context is clear.

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