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

Annotations declare readOnlyHint=false and idempotentHint=false but explain nothing; the description supplies the reason by stating a fixed 2900-credit charge against the API key balance, which tells an agent this call is billable and repeat calls are not free. It stops short of saying what happens on insufficient credits (error vs. partial result) or how large the pack is.

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?

Two sentences: contents first, cost second, fallback third, with no filler. Every clause carries distinct information an agent needs before calling.

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?

With no output schema, the description carries the return-value burden and does so by enumerating the included fields and the one-year record window. The credit mechanics are covered, but the failure mode on a short balance and the pack's size remain unstated.

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?

There is a single required 'place' parameter with 100% schema description coverage including an example id format. The description reinforces that the place is the scoping key for everything returned, but adds no syntax or validation detail beyond the schema, 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 description specifies the exact payload: all sources covering one place (publisher, original link, licence, reuse terms) plus a year of reuse-permitted records. That is concrete enough to distinguish it from get_source (one source) and search_records, though the retrieval verb itself is only implied by the name.

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?

It gives a fallback path when the balance is short ('use buy (product city_pack) or the REST URL with x402'), which is genuine routing guidance. It never says when to prefer this pack over searching records or fetching individual sources, so the main use-vs-alternative decision is left implicit.

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