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

Annotations already disclose the write profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false), so the safety bar is lower. The description adds a genuinely useful behavioral boundary about what a stored voice does NOT authorize (claims, guarantees, discounts, offers), but says nothing about overwrite behavior, required permissions, or the effect of omitting voiceTraits.

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 action, then parameter glosses, then the boundary rule. Nothing is padded, though the final sentence could have been tied more tightly to tool selection.

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?

An output schema exists, so return values need not be described, and annotations cover the safety profile. For a three-parameter write tool with zero schema description coverage, though, leaving brandId unexplained and not stating whether a save replaces prior voice data leaves the definition only adequately complete.

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 0%, so the description carries the burden, and it does explain two of three parameters: voiceSummary as 'the tone in plain language' and voiceTraits as 'short labels such as plain, specific, or calm.' brandId, a required parameter, gets no explanation at all, and no constraints (length limits, 20-item cap) are surfaced.

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 gives a concrete verb+resource: 'Store how this brand should sound.' It is clearly the write-side counterpart to check_brand_copy and get_brand_guide, and the domain boundary sentence further separates it from the save_approved_claim/save_offer siblings. It stops short of naming a sibling outright, so it is clear but not explicitly differentiated.

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?

There is a useful when-not signal: 'Voice does not approve a claim, a guarantee, a discount, or an offer,' which steers the agent toward save_approved_claim and save_offer. However, that boundary is phrased as a domain rule rather than tool routing, and there is no explicit when-to-use or named alternative, so guidance is implied rather than stated.

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