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

Annotations already cover read-only safety (readOnlyHint=true, destructiveHint=false). The description adds useful behavioral context beyond that: it promises live data, no auth or browser needed, and discloses the per-call cost ($0.02/call). This is meaningful added value without contradicting any 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?

The description is two sentences, front-loaded with the core action and resource, followed by concise practical notes. Every clause adds value; the pricing sentence is brief and does not distract from the primary purpose.

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 listing-pulling tool with rich annotations and a fully described 5-parameter schema, the description covers the essential context: source, location, filters, non-authenticated access, and cost. It does not describe the return format in detail, but the absence of an output schema is mitigated by the straightforward 'listings' concept and the schema's reference to 'listing rows'.

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 every parameter has a clear description (city path, deal_type enums, etc.). The description only restates the filter categories ('by deal type, property type and city') without adding novel semantic details, so it stays at the baseline for fully described schemas.

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 ('Pull') with a clear resource ('live apartment and house listings straight from Imovirtual.com') and specifies the filtering dimensions (deal type, property type, city). It unambiguously identifies the Portuguese real-estate domain, distinguishing it from country-specific sibling tools.

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 gives clear context: it is for Imovirtual.com listings in Portugal, and states practical benefits ('No login, no browser, no proxies') that help decide when to use it. It does not explicitly name alternatives or exclusions, but the Portugal-specific scope is immediately evident from the text and sibling context.

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