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

Annotations cover the safety profile (readOnlyHint=false, openWorldHint=true, idempotentHint=false), and the description adds genuinely new context: the actual draw happens off-tool on prismtect.com, the returned link is valid for 30 days, and the value constraints (min 0/1, max 99, at most 8 numbers). It doesn't say what happens when an invalid sentence or format is supplied, or whether links can be regenerated.

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?

Front-loaded with the target user and the deliverable (one link), then constraints and expiry. Mostly efficient, though the ranges sentence repeats what the schema enforces and could be trimmed.

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 seven-parameter link-builder with no output schema, the description conveys what is returned (a single URL) and its 30-day lifetime, plus the delegation of number drawing. A brief note on the return value's exact form and error behavior would close the remaining gap.

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 the schema already documents all seven parameters. The description's restatement ('the lottery format (a game, or custom count and max with optional extras)') and the range summary mostly duplicate schema constraints rather than adding semantics such as how a game preset interacts with supplied count/max.

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-and-resource: it produces one prismtect.com link encoding a user's sentence, and explicitly says 'this tool makes no numbers,' which distinguishes it from number-generating siblings such as pick_numbers. It never names those siblings, so the differentiation is inferential rather than explicit.

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 opening sentence gives a clear use case ('a user who wants lottery numbers drawn from a sentence of their own'), including the kinds of sentences accepted (wish, name, question). There are no exclusion cases or named alternatives telling an agent when to pick a sibling tool instead.

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