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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so safety is covered. The description adds significant behavioral detail beyond annotations: it explains the ranking order ('best first'), the reasons included (budget, surface, rooms, zone), and the filter condition (contacts with a 'recorded brief'). This gives the agent a clear picture of what the call does and what the response looks like, going well beyond the structured metadata.

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?

The description is two crisp sentences totalling about 25 words. The core action and output are front-loaded, and the second sentence adds a practical use context. Every word earns its place with no fluff or repetition.

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 read-only tool with two parameters and no output schema, the description conveys the essential return information: contacts ranked best-first with reasons. It also specifies the filter (recorded brief) and the use case. It does not mention pagination or limit defaults, but these are minor given the readOnlyHint and idempotentHint. The description is complete enough for an agent to call the tool correctly and interpret 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?

The schema description for propertyId is explicit and useful ('Exact id previously returned by a read tool — never invent one'), but the tool description itself adds no parameter-specific information. The limit parameter is self-evident from its name and min/max, and the schema coverage is 50%. Since the description does not compensate for the undocumented limit, but the schema partially does, a baseline score of 3 is appropriate.

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 states a specific action (matching contacts to a property), defines the input (listing) and the output (contacts ranked best-first with reasons such as budget, surface, rooms, zone). It clearly differentiates from the sibling match_properties_to_contact (reverse direction) and from generic list tools like list_contacts. The verb 'which contacts fit' is active and precise.

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?

The phrase 'The call list for a new listing' gives a concrete use case, implying the tool is for when you have a listings and want to identify which contacts to call. It does not explicitly name alternatives or state when NOT to use it (e.g., for the reverse match), but the purpose is clear enough from the description alone. A score of 4 reflects solid contextual guidance without explicit exclusion of alternatives.

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