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

With no annotations, the description carries the full burden — it explicitly discloses 'WRITE operation with personal data' and the mandatory consent gate. This flags both the mutating nature and the privacy sensitivity of the operation. It doesn't mention post-registration side effects like account creation or confirmation emails, but the critical safety traits are disclosed.

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?

Three short sentences with zero fluff: purpose, then critical safety warning, then workflow. The most important information (write nature, explicit consent, consent=true) is front-loaded ahead of the flow guidance. Every sentence earns its place.

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 17-parameter tool with no output schema, the description covers the essential decision factors: what the operation does, when to call it, the consent requirement, and the ordering relative to check_rental_chances. It doesn't describe return values or post-registration outcomes (confirmation emails, account creation) which the agent might need, but the critical prerequisites are all present.

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 59%, so the description partially compensates by emphasizing that consent must be true and by tying the score parameter to the check_rental_chances flow. However, it doesn't clarify the undocumented parameters (rooms, budget, income, locale, household, timeframe, location_type, workplace_address) beyond what their enum names imply. It adds value on consent but leaves the coverage gap unfilled.

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 (register) with a clear resource (Swiss tenant in Immoswipe Mieter-Pool) and a concrete purpose (property managers see profile and contact about matching units). It clearly distinguishes from all sibling tools, which are GET/search operations — only check_rental_chances is related, and the description explicitly differentiates the registration from it.

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?

Provides explicit when-to-use guidance: 'ONLY call after the user has EXPLICITLY agreed to join the pool' and 'Typical flow: run check_rental_chances first, then offer the sign-up.' It names the relevant sibling (check_rental_chances), orders the flow, and states the consent precondition, leaving nothing to inference.

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