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

Beyond the readOnly/non-destructive annotations, it discloses that summary and transcript are null or empty while analysis is pending or when the conversation is private, and that an unknown ID produces a not-found error. These are genuinely useful edge-case behaviors the agent could not infer from annotations, though it doesn't mention latency or size limits of the transcript payload.

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?

Front-loaded with the core action and the returned fields, then the usage routing, then edge cases. It is somewhat dense with sibling names, but each clause carries information; nothing is pure 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?

An output schema exists, so the field enumeration is bonus rather than a necessity; combined with the null-state and not-found behavior, an agent has enough to call and interpret this correctly. Only minor gaps remain (e.g., whether the returned transcript is truncated for long calls).

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 schema itself already says the callId is a UUID, not a phone number. The description mainly reinforces that the ID comes from app_listCalls/getCallHistory, adding little beyond the schema, so the 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 one call by its UUID") and enumerates the payload it returns (caller/recipient, status, minutes, AI summary, transcript turns, webUrl). The sibling/alternatives (getCallDetails, getCallHistory, search) are named as different tools, so an agent can distinguish this from them without opening a schema.

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 says to use it after app_listCalls or openCallsInbox returned the call id, and explicitly routes to getCallDetails for a shareable recording link and to getCallHistory/search to find a call first. Both when-to-use and when-to-use-something-else are stated.

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