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

The description discloses critical behavioral constraints beyond the annotations: the need for explicit consent, sharing details with a third-party advisor, and requiring international phone format. It emphasizes 'never assume consent' and 'Only call with consent=true after they say yes.' This adds significant context that annotations (readOnlyHint=false, openWorldHint=true) do not cover.

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 every sentence earns its place. It starts with the core purpose, then provides usage guidance, prerequisites, and consent handling. The use of caps for key directives ('OFFER THIS ONLY', 'MUST ask', 'Never assume') improves scannability without being verbose.

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 tool with 10 parameters and no output schema, the description covers the essential invocation context: when to call, what to collect, and the consent gate. It does not describe the return value or post-call behavior, but these are not always required. The missing piece is a brief note on what happens after the request is registered (e.g., 'the advisor will contact them'), which would make it fully complete.

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?

The input schema has 100% parameter description coverage, so each parameter is already documented. The tool description reinforces the consent and phone format requirements but does not add new semantic meaning beyond what the schema provides. Baseline 3 is appropriate since the schema carries the heavy lifting.

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 clearly states the tool's purpose: 'Register a buyer's request to be contacted by a local Portuguese property advisor.' It uses a specific verb ('register') and identifies the resource (advisor contact request). This distinguishes it from siblings like get_property_contact, which likely returns contact info, and search_properties, which is for searching.

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 explicit when-to-use ('when the user signals intent to move forward') and when-not-to-use ('Do NOT offer it while they are still just browsing or comparing') guidance. It also lists prerequisites (ask for name, email, phone, consent). However, it does not explicitly name alternative tools for comparison, so it stops short of a full 5.

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