L50 UK Data API

tenders buyer

tenders_buyer

Read-only

A UK public buyer's contracts (Contracts Finder, England): spend by year, median contract value, top suppliers with their share, main categories, tenders open for bids now and the 25 most recent awards. Costs $0.05 per call, paid in USDC on Base with x402.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "name": "<name>"
    },
    "name": "tenders_buyer"
  }
}

Input Schema

Name	Required	Description	Default
`name`	Yes	Buyer name, e.g. Leeds City Council
`years`	No	How many years back (default 3)

Schema Changelog

Changes observed during successful MCP inspections.

AddedNov 9, 2026

TDQS

A3.8/5.0

Behavior4/5

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

Annotations already declare read-only and open-world behavior, so the safety profile is covered. The description adds genuinely new context beyond the annotations: a $0.05 per-call cost paid in USDC on Base via x402, which an agent must know before invoking, plus an explicit cap of '25 most recent awards' on the results. It does not discuss pagination or failure modes, but for a paid read endpoint this is solid disclosure.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences: the first front-loads the resource and enumerates outputs, the second states cost and payment rail. Every clause carries information, and the pricing detail is placed last where it does not obscure the primary purpose. Dense but not padded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description takes on the job of describing returns and does so by enumerating the exact facets delivered, including result limits. It also covers cost, payment mechanism, data source, and geographic scope. Nothing an agent needs in order to decide to call it or interpret the response appears to be missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so both the 'name' and 'years' parameters are already documented in the schema with an example and a default. The description's 'spend by year' phrasing loosely corresponds to the years window but adds no syntax, format, or matching-behavior detail. Baseline 3 applies 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.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific resource (a UK public buyer's contracts from Contracts Finder, England) and enumerates the returned facets: spend by year, median contract value, top suppliers and share, categories, open tenders, and the 25 most recent awards. An agent knows exactly what data comes back. It does not explicitly contrast itself with the sibling tenders_supplier, which keeps it at 4 rather than 5.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied rather than stated: the caller supplies a buyer name and gets that buyer's profile, and the 'England' qualifier usefully scopes when the tool applies. There is no explicit when-to-use guidance, no exclusion for buyers outside England or for supplier-side queries, and no pointer to an alternative tool for those cases.

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

All L50 UK Data API tools Inspect

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