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

Annotations only say readOnlyHint=false, destructiveHint=true, openWorldHint=true; the description goes well beyond that with the Slice sign-in requirement on first use, the hard-coded destination (only the confirmed email on that account, never another address), the one-time-per-transcript limit, and the requirement that it be sent from the originating conversation or account. These are exactly the operational constraints an agent cannot infer, and nothing contradicts the destructive/open-world hints.

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?

Four short sentences, each carrying a distinct constraint (eligibility, auth, destination, lifetime) with the most important gating rule front-loaded. No filler or repetition of 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?

With one simple parameter, full schema coverage, and an output schema (so return values need no explanation), the description covers everything an agent needs: prerequisites, destination restriction, idempotency limit, and the negative case routing to sharing. Nothing material is missing.

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 description coverage is 100% and the single parameter (transcription_id) is already documented in the schema as a finished transcript's ID. The description reinforces 'finished transcript' but adds no syntax, format, or sourcing detail 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?

Names a specific verb+resource ('email a transcript') and immediately scopes it to a finished transcript. It also implicitly separates itself from creation tools like transcribe_audio and transcription_status by requiring an already-finished transcript as input.

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 an explicit trigger ('only when the user explicitly asks for a finished transcript to be emailed'), explicit exclusions ('Do not use to send a transcript to somebody else'), and a named alternative action ('share the results page instead'). It also states the per-transcript and per-account conditions that gate use.

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