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

Beyond the readOnlyHint the description adds genuinely useful behavior: the recording link is signed, MP3 format, and expires after one hour, and speaker attribution includes handoff participants. These are details an agent cannot infer from annotations or schema and materially affect how it should handle the link.

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?

A single dense sentence with the payload front-loaded and zero filler. It is slightly run-on with the nested parenthetical, but every clause carries information an agent needs.

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?

No output schema exists, so the description carries the return-value burden and does so fully: both transcript forms, summary, outcome, and recording format with expiry. Combined with 100% parameter coverage, an agent has everything needed to call it 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?

Schema coverage is 100%, so both parameters are already documented, and the description restates the id guidance rather than adding format or edge-case detail. The optional `recording` toggle is only implied by the mention of a signed link, which the schema already covers, so 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?

Opens with a specific verb+resource and scope ("One call in full") and enumerates exactly what is returned: transcript text, timed speaker lines, summary, outcome, recording link. It is immediately distinguishable from list_calls, the sibling it names.

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?

"Pass an id or call SID from list_calls" establishes the correct upstream workflow and implicitly positions this as the single-call counterpart to list_calls. It stops short of explicit when-not guidance (e.g., that bulk retrieval requires list_calls), so it is clear context but not a full routing rule.

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