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

Annotations already cover the safety profile (readOnlyHint, destructiveHint false, openWorldHint). The description adds a real behavioral fact beyond them: the Cotlet API key / app-access requirement. Some content just restates the read payload, but the auth note is genuine added value.

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-loads the core content ('Full listing: ...') and stays to a few meaningful sentences. The field enumeration is a bit list-like but each clause maps to what the caller gets, so little is wasted.

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?

No output schema exists, so the description carries the burden of describing returns, and it does so by listing the field categories returned. It also flags the auth requirement. Coverage is good, though exact response shape is only described by example rather than precisely.

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?

With one parameter at 100% schema description coverage, the schema fully documents listing_id ('Listing ID from list_listings'). The description adds nothing about the parameter, so baseline 3 applies.

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 ('Get listing', 'Returns one listing') and enumerates the payload (address, price, details, photos, EPC, floorplans). It implies a single-item detail fetch that contrasts with list_listings, but never names that sibling to make the distinction explicit.

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 workflow guidance: 'Use it before update_listing so your agent changes only what you asked for.' This tells the agent when to reach for it relative to a mutation sibling, though it offers no exclusions or other alternatives.

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