current_vs_historyStats for one destination (min, median, and what share of the TRACKED DAYS were dearer than the last measurement) without the sample points. Percentages are over observed days, not over the calendar span. Descriptive only: it does not say whether to buy.
| Name | Required | Description | Default |
|---|---|---|---|
| destination | Yes | destination slug |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With readOnlyHint=true already declared, the description adds valuable behavioral context: percentages are over observed days rather than the calendar span, and the tool is descriptive only and does not recommend whether to buy. This goes beyond the annotation without contradicting it.
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 dense, purposeful sentences. The first front-loads the core statistics and output scope, and the second clarifies the percentage basis and adds a non-advice caveat. No unnecessary words.
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 simple one-parameter read-only tool with no output schema, the description fully describes what is returned and how to interpret it. The destination slug is already defined in the schema, so nothing essential is missing for correct invocation.
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 schema already documents destination as a required slug with 100% coverage. The description only says 'one destination' and adds no additional semantic details about the parameter, so it remains at the schema-coverage baseline.
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 names the resource (one destination) and the exact statistics returned (min, median, share of tracked days dearer than the last measurement), and explicitly says the sample points are omitted, which distinguishes it from a price-history tool. It lacks an explicit verb, but the intended operation is unambiguous.
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 phrase 'without the sample points' implies that price_history is the better tool when sample points are needed, and 'Descriptive only' warns against using this tool for buy decisions. However, it never explicitly names sibling tools or gives concrete selection criteria beyond these implications.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
list_destinations is clearly a discovery tool, while price_history provides the full series and current_vs_history provides a comparative summary. There is some overlap because both single-destination tools report stats, but the stated outputs are distinct enough for an agent to choose correctly.
list_destinations follows a verb_noun pattern, but price_history and current_vs_history are noun phrases with no consistent verb. The names are readable and reasonably descriptive, but the mix of conventions prevents a higher score.
Three tools is on the small side, but each covers a meaningful slice of the price-history workflow: enumerate available series, inspect a series, and get a current-vs-history summary. It is slightly sparse but not unreasonably so for a focused read-only server.
The server covers discovery and per-destination historical detail, plus the headline comparison statistic, so core read-only use cases are supported. Obvious gaps such as raw full-resolution series, cross-destination comparison, or any write/live-quote operations are absent but appear to be out of scope.