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

Annotations already declare read-only and open-world, so the safety profile is covered. The description adds genuinely non-obvious context: a metered price of $0.002 USDC per successful call, the x402 payment rails (Base, Solana, Arc), and the guarantee that failed calls are not charged. What it omits is anything about result ordering or truncation behavior, but the paid-call disclosure is the more important gap it fills.

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?

Everything is front-loaded: the resource and prefix semantics come first, the output scope second, pricing last. It is dense but each clause carries information. The phrasing 'template title, page ID and link' is slightly compressed and could read as an aside, but no sentence is wasted.

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?

An output schema exists, so the description need not explain return shape — and it still summarizes it. Between the scope exclusion, the prefix example, and the pricing/charging model, an agent has everything needed to decide to call it and to predict the cost of doing so.

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 both limit and prefix are already documented with ranges and constraints. The description adds only the illustrative prefix values ('Cc-zero or Cc-by-sa'), which marginally helps an agent construct a valid prefix but is mostly redundant. Baseline 3 is appropriate when the schema carries the parameter burden.

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 resource (Wikimedia Commons license template names in the Template namespace), the exact filter semantics (prefix match, with 'Cc-zero'/'Cc-by-sa' examples), and what is returned (template title, page ID, link). It also bounds scope negatively: 'Names only, not the license texts or usage rules.' An agent can tell exactly what this returns without opening the schema.

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 'Names only, not the license texts or usage rules' clause implies the right use case (discovering license template identifiers, not fetching license content), but it is a scope statement rather than explicit when-to-use/when-not guidance. No alternative tool or fallback path is named for cases where the agent actually needs license text or usage rules, so the routing signal is only implied.

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