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

Annotations already declare readOnlyHint=true, openWorldHint=true, destructiveHint=false, so the safety profile is covered. The description adds real behavior beyond that: it enumerates what the result carries (claim state, source freshness, accreditation names, canonical profile URLs) and explicitly disclaims availability claims, mixed-source ratings, and any contact action — useful boundaries an agent could not infer from annotations alone.

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 sentences with no filler, and the core purpose is front-loaded before the return/boundary clauses. The second sentence is a dense run-on list, but every element (returns, disclaimers) carries information rather than restating the name.

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 an output schema present and annotations covering the safety profile, the description only needed to convey search semantics, result character, and boundaries — all of which it does. A small residual gap is the lack of explicit sibling routing, but nothing needed to call the tool correctly is missing.

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 75%, above the midpoint baseline, so the schema largely documents trade, location, and postcode itself. The description echoes the optional 'postcode or place' scoping but adds no syntax, format, or limit semantics beyond the schema (the undocumented 'limit' parameter is also untouched). Baseline 3 is appropriate.

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 ('Find current public Tradehand directory listings') and the scoping facets (trade, optional UK postcode or place). It is clearly a directory search, but it never names or contrasts with the nearest siblings (browse_trades, get_trader), so the agent must infer the boundary itself.

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 implied by 'by trade and optional UK postcode or place', and the negative clauses ('does not claim availability, expose mixed-source ratings, or contact anyone') set expectations about what the result means. However, there is no explicit when-to-use-this-vs-browse_trades-or-get_trader routing guidance, which is the main gap.

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