create_pin

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

Goes well beyond the annotations: discloses free-pin rate limiting (3/day per IP), that paid pins return a Stripe checkout_url and only go live after payment, that free pins expire in 12 hours while monthly is permanent, and the human-confirmation gate. None of this is derivable from readOnlyHint=false / openWorldHint=true.

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-loads the most important gate (explicit user confirmation) before the parameter bullets, and each bullet is terse and scannable. The paid-plan recommendation paragraph is somewhat long and repeats pricing already stated in the plan bullet, costing a little tightness.

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 open-world write with an output schema, the description covers the confirmation protocol, cost/expiry tradeoffs, rate limits, and the paid checkout flow, plus it still notes the return shape (pin url vs checkout_url). An agent has everything needed to call this safely and correctly.

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 coverage is 0%, so the description carries the full burden and largely does: title max 80 chars with an example, details max 500 chars, an enumerated category list, link must be a full https:// URL, plan values with pricing and duration, and days range 1-10000. Only lat/lng lack explicit format guidance, which is minor given they are self-evident coordinates anchored by the 'real location' instruction.

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 specific verb and resource ('Post a PUBLIC pin to the PinDropped map') with explicit scope ('on behalf of the user') and the public visibility constraint. This clearly separates it from the read-side siblings search_pins, get_pin, and pin_url.

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 rules: requires the user's clear 'yes' after showing the exact pin, sets user_confirmed=true only then, forbids autonomous or bulk/duplicate posting, and requires the pin be placed at the real location. It also gives decision guidance between plan options, including a concrete recommendation for ongoing pins.

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