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

While annotations already signal readOnlyHint=false and openWorldHint=true, the description adds meaningful context beyond them: this tool returns a 402 payment challenge when paymentHeader is absent, is unsigned and vouches for nothing, is not a remedy, and costs $0.002 USDC on Base via x402. This is valuable behavioral disclosure beyond annotations. The readOnlyHint=false is consistent with a paid tool; no contradiction.

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?

The description is compact and front-loads the core value proposition, but it packs a lot into a dense stream with several capitalized USE ... INSTEAD phrases. The multiple sibling references are useful but make the text slightly run-on. Still efficient for a tool with nuanced routing and payment behavior.

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 2-optional-parameter tool with no output schema, the description covers the key scenario (payment challenge when no proof), the exact distinction from three sibling tools, the cost, the unsigned nature, and the non-medical disclaimer. An agent can reasonably decide when to call this and understand what to expect. The absence of an output schema is compensated by the prose description of returned fields (line, id, seed).

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 both optional parameters (intent and paymentHeader). The description adds meaningful behavioral context around paymentHeader (that its absence returns the 402 challenge as a quote, not an error) and intent (recorded verbatim), which goes beyond the schema. However, this guidance is mostly embedded in prose rather than per-parameter, and the schema already covers the basics, so baseline 3 fits.

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 identifies a specific resource (clinic_seed/clinic_line output) and the key added value: it returns the same encouragement, its id, and the seed for exact regeneration. It distinguishes this from clinic_hug and clinic_line by name and by exact functional difference (seed added over clinic_line).

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?

Provides explicit routing: use clinic_hug if only words are needed, clinic_line if a handle suffices and no remake is needed, and clinic_keepsake if a stranger must verify it later. This covers when-to-use and when-not-to-use alternatives clearly.

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