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

With no annotations, the description carries the full burden and does well: it discloses the return shape (full-res signed PNG & JPEG download URLs plus inline preview), free-tier fair-use limits, and a daily capacity reset at 00:00 UTC. It omits other behavioral details an agent might want, such as signed-URL expiry, authentication prerequisites, and failure behavior when capacity is exhausted.

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 sentences, each carrying distinct information: output shape first, then limits, then required input, then defaults. The closing defaults sentence partially duplicates schema defaults, keeping it just short of a 5.

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 9-parameter generation tool with full schema coverage and no output schema, the description covers output format, limits, required inputs, and defaults well. It leaves minor gaps around choosing between the two photo inputs and the singular-vs-plural sibling distinction.

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%, so every one of the 9 parameters is already documented in the schema, including enum values and defaults. The description restates the 'sage' theme and '1:1' ratio defaults but adds no guidance on, for example, when to prefer photoUrl over photoBase64, 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?

States a concrete verb (Generate) and a well-defined resource (Cherishly keepsake tribute card) built from name, dates, photo and message, which is far more than a restatement of the name. It does not, however, address the sibling tool generate_tribute_cards (plural), so an agent has no in-description basis to choose between the singular and plural variants.

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?

The description gives useful calling guidance ('Only the person's name is required; ask only for essential missing details') and states the fair-use/capacity conditions under which free generation is available. It never says when NOT to use this tool or routes the agent to the plural sibling, so usage is implied rather than explicit.

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