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

Annotations already cover the safety profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false), and the description adds real context beyond them: it is free (no generation credit), takes a few seconds per new piece, and only reads new/changed pieces once. Error behavior and what the index looks like afterwards are left implicit.

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?

Two front-loaded sentences with no filler; the core action and its incremental nature come first, then cost and timing. The second sentence is a long compound clause, but each element (cost, duration, sequencing) earns its place.

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 single-parameter, no-output-schema tool, the description covers what it does, its cost, its duration, and the correct next call. Missing only the profile_id semantics and any failure/edge-case behavior, which are minor given the simple contract.

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?

One required parameter with 0% schema description coverage, so the description carries the burden but only implies scope via 'the profile's latest drafts and samples'. It never states that profile_id selects which profile's pieces are synced, leaving the single parameter under-specified.

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 ('Bring the Voice Brain up to date... each new or changed piece is read once'), and the incremental, one-pass indexing behavior distinguishes it from the manual add_to_memory sibling. It also names get_memory as the follow-up read, so an agent can place it in the workflow 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?

Gives explicit timing ('run it after finalising drafts, then call get_memory'), which is actionable sequencing. It does not state when NOT to use it (e.g. versus add_to_memory for a single piece), so it stops short of full when/when-not guidance.

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