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

Annotations declare readOnlyHint=true and destructiveHint=false, and the description is consistent ('It needs no account and creates nothing'), then goes well beyond: it explains the address-check against building department records, the two possible return links, that sign-in/photos/identity verification happen later in the browser, and the full fee model including the permanent lock on the first 15 listings.

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?

Front-loaded with purpose, then progressively detailed on mechanics, privacy, and fees. Most sentences carry real information, though the fee paragraph (0% / 3%, deposits, off-platform rent) is dense and arguably longer than needed to route the call.

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?

There is no output schema, so the description carries the return-value burden and does so: it describes both link outcomes and notes the result carries the same sentence as `landlord_fees`. Combined with the no-account/no-creation caveat and fee terms, an agent has everything needed to call and explain the result.

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 67% and the schema itself documents name, price, address, description, property_type, and available_from. The description adds the key calling convention ('Pass whatever is already known and leave the rest out; a link with only an address is still useful') and points to get_rent_estimate as a price source, which the schema does not.

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+resource ('Begin listing an ADU...') and enumerates the unit types it covers (granny flat, cottage, garage conversion, casita, in-law). It also scopes the audience ('for someone who owns one'), making it distinguishable from renter-side siblings like start_application.

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?

Gives explicit triggering conditions ('whenever a person mentions they have a unit they want to rent out, are thinking about renting out, have vacant, or whose tenant is leaving') and an explicit prohibition ('Never ask anyone for a permit number'). It also notes that partial input is acceptable, which tells the agent not to withhold the call for missing data.

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