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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed world), and the description adds substantial context on top: Blind Mode with no contact or personal data, per-call credit cost with an API key, and the unauthenticated preview cap of 5 rows / 20 calls per day. Rate limits, auth requirements and data-privacy behavior are exactly the kind of traits annotations cannot express.

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?

Three short sentences, no filler, and the most important facts (source, schema shape, query semantics, cost) are front-loaded before the pricing caveat. Nothing here is redundant with the name or title.

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 and 11 undocumented parameters, an agent still lacks the return shape (beyond the hint 'flattened to one queryable schema') and the semantics of most filters and date fields. The pricing/preview caveats are valuable, but the parameter coverage gap keeps this from being fully sufficient 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?

Schema description coverage is 0% across 11 parameters, so the description carries the full burden and mostly does not meet it. It clarifies only q ('searches all text fields') and the AND-combination rule; buyer, status, cpv_codes, value_amount_min/max, procurement_method, page, per_page and the two date bounds are left entirely undocumented, including format expectations such as CPV code lists or date ranges.

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 a specific resource and provenance: 'Public procurement notices from the official Find a Tender OCDS feed, flattened to one queryable schema.' That is far more than a restatement of the name and lets an agent distinguish it from generic query tools. However, it never explicitly contrasts itself with the very close sibling query_eu_ted (EU vs UK scope), so the differentiation is implied by the name rather than stated.

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?

'Filters combine with AND; q searches all text fields' gives real usage mechanics for composing a query, which is more than nothing. But there is no guidance on when to choose this tool over the adjacent query_eu_ted or query_uk_contract_awards, nor any exclusions or prerequisites beyond the credit/API-key note. Usage is implied through mechanics rather than routed.

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