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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds a genuinely non-obvious behavioral detail: the response includes a signed public share link to the call page, which is a shareable artifact the agent should know about before surfacing it. Minor gaps remain (behavior when the UUID is invalid, transcript size/truncation).

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?

Two sentences, front-loaded with the core action, and the routing sentence sits at the end where it belongs. The return-field enumeration is long but earns its place because no output schema exists; the only cost is that the first sentence is a dense run-on.

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 one parameter, no output schema, and no nested objects, the description carries the right load by describing the response shape in prose. It stops just short of full completeness because it says nothing about failure modes for an unknown UUID or whether the transcript is truncated.

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 single callId parameter is already documented as a UUID from getCallHistory or search, not a phone number. The description reinforces that provenance but adds no new syntax or format meaning beyond the schema. 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 everything about one call by its UUID") and then enumerates exactly what comes back: status, time, receptionist, AI summary, transcript, and a signed share link. The inbound/outbound auto-detection is called out, which distinguishes it from tools that require a direction or phone number.

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?

Explicitly sequences the tool: "Use it after getCallHistory, search or get_contact_timeline gave you the call id." It also names the alternatives and their selecting conditions — getCallHistory to list calls, search to find one by name, phone or topic — so an agent can route without guessing.

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