Zovo Birth Stats Poster

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

Annotations cover safety (readOnly, idempotent, non-destructive), and the description adds real operational context beyond them: the output is a print-ready PDF, the supported sizes, dual-unit weight/length rendering with conversion constants, moon phase and sunrise/sunset derivation, and the refusal rule for towns not in the city list. The coordinate-plus-IANA-timezone requirement for sunrise/sunset is a genuine behavioral constraint an agent could not infer.

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?

It is one dense paragraph but front-loaded with the trigger, then output, then dependencies, then scope limits — no filler sentences. Minor redundancy with the schema (size list, conversion factors) keeps it from 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 16-parameter generation tool with an output schema and full annotations, the description covers the remaining gaps an agent needs: what gets produced, size/theme options, data that must be self-extracted from user input, and the specific failure mode (unlisted town) with its workaround.

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 each of the 16 parameters is documented in detail in the schema itself, including date-format disambiguation and place/coordinate syntax. The description mostly restates that field-per-detail structure and the moon/sun prerequisites, adding little meaning the schema does not already carry, 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?

The first sentence names a specific artifact (a birth stats poster / announcement printable / nursery print / birth stats sign) and the trigger condition for producing it. An agent knows exactly what this tool creates and can map varied user phrasings onto it.

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?

Explicit when-to-use phrasing ("Use this when the user wants...") is paired with exclusions ("Does not add photos or footprints") and an instruction to extract details from a pasted announcement or hospital-card photo rather than asking field-by-field. With no siblings, the boundaries are fully drawn.

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