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

Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds real value by disclosing the return payload (transcript lines, summary, recording link), which matters because there is no output schema. The phrase 'one-hour recording link' is ambiguous — expiry window versus recording length — and no size or truncation behavior for long calls is mentioned.

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 tight sentence with the resource and the payload front-loaded. Every clause contributes and nothing is wasted or repeated from the title.

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 one-parameter read-only lookup with no output schema, the description broadly covers what the agent will receive. It stops short of noting behavior for long calls (truncation or pagination) and what happens when the id is unknown, which are the remaining gaps given the tool's simplicity.

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 'id' parameter is already documented as 'Call id or call SID from my_calls.' The description adds nothing further about the parameter, so baseline 3 applies — the schema does the heavy lifting here.

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?

The description names a specific resource ('one call in full') and enumerates exactly what comes back: speaker-and-time lines, the summary, and a recording link. That distinguishes it from the listing siblings (my_calls) and from the metadata-oriented 'call' tool, though the verb is implicit rather than stated as 'fetch' or 'retrieve'.

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?

Usage is implied by the resource description, but there is no explicit when-to-use or when-not-to-use guidance, and no routing to alternatives such as 'call' (for metadata) or 'my_calls' (for listing) when the full text isn't needed. The agent must infer that this is the tool to reach for only after it already has a call id.

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