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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the description correctly spends its space on data semantics: rebuilt weekly, 24-month window, notice links, coverage, page link and citation. It does not mention error behavior for an unknown country/kind, but for a read tool the added context is solid.

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?

Front-loaded with the resource definition, and the long enumerative second clause earns its place by listing the actual card contents rather than padding. It is dense and list-like but not wasteful.

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 full burden of describing return values, and it does so item by item (awards, competition, winners, SME share, buyers, trend, open calls, contracts, coverage, link, citation). An agent knows what it will get before calling.

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 100%, so all four parameters including enums are documented; baseline is 3. The description adds only a little beyond the schema, notably that format=markdown returns the same card rendered as Markdown, which reinforces the already-documented enum.

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 specific verb and resource ('One market card (country x kind of work)') and, via the singular 'one' plus the sibling list_markets, an agent can tell it returns a single card rather than a list. The scope is concrete and distinguishable from siblings.

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?

Usage is only implied by 'One market card' and the singular framing; there is no explicit 'use list_markets to enumerate, get_market for one card' routing statement or prerequisite note. The only explicit alternative mentioned is format=markdown vs default json, which is a format switch rather than a tool-selection guide.

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