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

Annotations only give the generic readOnly=false/destructive=false/idempotent=false profile. The description adds real behavioral context: the return value is a URL, the draft is owned by the signed-in person, and photos, identity verification and bank details are not required to publish. It does not explain what happens if the address falls outside the served markets.

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 the core action, then constraints in descending importance. Four sentences with no filler, though the eligibility list is dense and could be tightened.

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 10-parameter creation tool with no output schema and only 50% schema coverage, the description covers the essentials an agent needs: what is created, what is returned, what the draft deliberately does not do, and the geographic and price gates. Remaining optional parameters are self-evident from their names.

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 50%, but the description adds constraints the schema does not encode, notably that the address must fall within Los Angeles County, San Francisco, San Diego County or New York City, and that rent must exceed $0. It says nothing about bedrooms, bathrooms, square_feet, property_type or available_from, which remain undocumented.

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States a specific verb and resource with scope: 'Create an unpublished draft rental listing owned by the signed-in person.' This distinguishes it from a publishing action, but it never names the sibling 'start_listing', leaving the draft-vs-start boundary to inference.

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?

Explicitly frames when this tool is the right one ('Publishing is never done here') and enumerates the conditions the owner must satisfy later in the browser. It lacks explicit routing to an alternative tool for the publish step, so it is clear context without exclusions.

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