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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), so the marginal burden is low. The description adds genuinely useful state semantics beyond the annotations: in_progress while the call is live and no_transcript only after the conversation ends with no stored text.

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 short sentences, front-loaded with the core behavior and the negative scope right after. Every sentence carries information; the only minor cost is the slightly repetitive status phrasing.

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 tool with no output schema, the description supplies the missing return-state information (in_progress vs no_transcript) that the schema cannot. It stops short of stating what a successful transcript payload looks like beyond 'text', but that is a minor gap.

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 call_id parameter has no schema description (0% coverage) and is never mentioned in the description. The phrase 'for a phone call' implicitly signals what must be identified, but no format or lookup guidance is added, so it does no more than the schema's required-fields list.

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 (returns stored transcript text for a call) and immediately delimits scope with 'Does not start a new transcription.' That negation cleanly separates it from the sibling request_transcript without requiring the agent to open either 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?

Gives clear conditions for the tool's use and explicitly rules out the transcription-starting case, which is the main confusion risk. It does not, however, name the alternative (request_transcript) so the agent must infer where the excluded case belongs.

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