get_market_overview

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered structurally. The description adds genuinely non-obvious behavioral context: coverage gaps in the underlying data (marketType unknown for ~55% of records, transaction_date missing for ~1.7%), which materially affect how an agent should interpret the breakdowns. It does not discuss response size, aggregation lag, or freshness, leaving a small gap.

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, front-loaded with the entry-point instruction and the disambiguation before the enumeration of outputs. Every clause carries information — the negated use case, the sibling redirects, the returned fields, and the data-quality caveats — with no filler.

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 input parameters and no output schema, the description carries the burden of describing the return payload, and it does so by enumerating counts, date range, breakdowns, top locations, and price statistics. Combined with the data-quality caveats, an agent has enough to decide to call it and to interpret the result.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline for a parameterless tool applies. The mention of marketType refers to a returned field rather than an argument, so it neither helps nor confuses parameter semantics.

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 clear verb/resource ('shape of the whole Polish transaction database') and explicitly negates the likely misreading ('not one place'), then enumerates exactly what comes back: total count, date range, breakdowns, top locations, price statistics. Sibling tools get_price_statistics and search_transactions are named as the per-place alternatives, so the agent can distinguish this from neighbors without opening a 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 opening imperative 'Start here' gives an explicit entry-point rule, and the parenthetical names the alternatives (get_price_statistics, search_transactions) plus the condition that selects them (per-place queries). Both when-to-use and when-not-to-use are stated.

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