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

With no annotations, the description carries the full burden. It usefully discloses data origin (transcript extract + domain dictionary), persistence (pbx-index), and auth scope (x-temsor-pbx-key), plus a cost note ('Idle $0'). However it omits pagination/return behavior, and trailing claims ('No DID sales', 'Right-to-erasure ready', 'own PBX/Asterisk stays on customer') are marketing rather than operational disclosure.

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 first sentence is well front-loaded, but the query-string echo duplicates the schema and three trailing sentences ('Idle $0. No DID sales. Right-to-erasure ready. Advanced: own PBX/Asterisk stays on customer') are sales copy that does not help an agent select or invoke the tool. Several sentences fail to earn their place.

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 5-param list tool with no output schema and no annotations, the description covers source and scoping but does not describe the shape of returned facts or pagination behavior. Adequate but with clear gaps for an agent needing to interpret results.

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 description coverage is 100%, so the schema already documents q, kind, limit, domain, and call_id. The description largely restates the same filter names and a partial domain enum, adding no format or syntax detail beyond the schema — the correct baseline of 3 when the schema does the heavy lifting.

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 (List) and resource (extracted facts) plus example fact types (IMEI, room, tariff) and the source (durable index). It implies the read/list role against the singular pbx_facts_get sibling but never names it explicitly, so sibling differentiation is only partial.

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 filter dimensions (call_id, kind, domain, q) imply how to narrow results, but there is no explicit when-to-use or when-not-to-use guidance versus pbx_facts_get, pbx_search, or pbx_dictionary. Usage is left to inference from the parameter list.

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