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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false). The description adds genuinely non-redundant behavior: an entitlement constraint ('Intelligence plan and above') and a concrete enumeration of what is returned (winner, value, date, price guide). It does not disclose fallback behavior when no past contracts exist, which keeps it short of a 5.

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?

A single sentence that front-loads the primary payload (who won) and appends the use case and plan gate last. Dense parenthetical asides are readable, though the trailing 'Intelligence plan and above' and 'useful when...' clauses are tacked on rather than integrated.

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 correctly spends its words describing the return contents and the access tier required. For a one-param read-only tool this is close to complete; only empty-result handling and output format detail are absent.

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%, so the description must carry the burden, but 'For a tender' only loosely implies that tender_id identifies the tender being investigated. With a single self-evidently named integer param, the gap is minor, but no format, type, or lookup semantics are added beyond the schema.

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 very specific resource and output set: the incumbent/last winner for a tender, the buyer's closest past contracts (winner, value, date), and a price guide. No sibling tool (my_bids, search_tenders, get_tender) covers this, so it is distinguishable. It loses a point only because the action verb is left implicit in a noun-heavy phrase rather than stated directly.

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?

It offers one situational cue — 'useful when the notice publishes no value' — which implies a context for calling it, but names no alternative tool and gives no explicit when-not guidance. The Intelligence-plan gating is a prerequisite rather than usage routing. Adequate but clearly incomplete compared to a tool that names its alternatives.

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