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

Annotations already establish readOnly/idempotent/non-destructive behavior, so the description only needs to add context beyond that. It does: it documents return coverage (active/sold/expired), a data limitation (contact details omitted), and price semantics (USD with original currency fields). No contradiction with annotations.

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 sentences, each serving a distinct purpose: core operation, status scope, and output semantics/limitations. Front-loaded and free of filler.

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 simple single-parameter read tool with no output schema, the description covers scope, notable omissions, and price conversion. It doesn't describe error behavior or a full field list, but the annotations and input schema cover safety and parameter origin, making it adequately 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?

Schema coverage is 100% and the id parameter is clearly documented as a listing UUID sourced from search_listings. The tool description mostly repeats 'UUID' rather than adding new input semantics; its price/currency remarks concern output fields, not the input parameter.

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 action ('Fetch full details') with a precise target ('a single listing by its UUID'). Also delimits scope by listing statuses (active, sold, expired), which distinguishes it from search_listings and other platform-level sibling tools.

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?

Usage is implied rather than explicit: the description indicates the tool is for fetching one known listing by UUID, and the schema points to search_listings as the source of that UUID. However, it never explicitly states when to prefer this tool over search_listings or when not to use it, so the agent must infer the decision context.

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