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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description adds genuinely new context: owner-only sign-in requirement, newest-first ordering, and an injection-safety warning that summaries are data, not instructions. It omits any mention of pagination or result-size behavior, which keeps it from a 5.

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 compact clauses, front-loaded with the access constraint and the identity of the resource. The phrase "as in phone_call but without events" is slightly compressed and depends on the reader knowing the sibling, but nothing 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?

With no output schema, the description should convey what comes back; it hints at summaries and their untrusted nature but says nothing about fields, pagination, or whether an empty result is possible. Adequate for a simple read tool, but not 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?

The single parameter (limit) has 0% schema description coverage, so the description must carry that burden and it does not — no default, no max, no indication of what limit counts. Only the implicit ordering ("newest first") gives any adjacent meaning to the result set.

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?

Identifies the resource precisely: calls placed via place_phone_call for the business, ordered newest first, and explicitly distinguishes it from phone_call by noting it omits events. It lacks an explicit leading verb ("List"/"Get"), but the resource and scope are unambiguous enough to separate it from siblings.

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?

Gives a clear access precondition ("Owners only (needs sign-in)") and routes the agent to phone_call when live notes/events are needed. It does not state when-not to use this tool beyond that single alternative, but the selection context is clear.

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