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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful domain context (why suppliers lack product catalogues, so keyword search over capabilities is the mechanism), but says nothing about result count, pagination, ranking, or how the default limit of 10 behaves.

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, zero filler. The capability-facet enumeration comes first so the agent can pattern-match immediately, and the second sentence supplies the domain rationale that justifies the tool's existence rather than padding.

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 should carry more of the burden of explaining what comes back — it never indicates whether results are supplier summaries, whether they include certifications/contact details, or how the limit interacts with total matches. The input side is adequately covered by the schema plus description facets.

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 coverage is 75%, so most parameters are self-documented. The description maps facets (process, material, certification, category, country) onto the inputs, clarifying that material/category must go through the free-text 'query' since no dedicated parameters exist — helpful, but it never mentions the 'limit' parameter or result shaping.

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 companies that can make something') and enumerates the facets searched: process, material, certification, category, country. It is clearly distinguishable from siblings like search_parts or get_supplier, which operate on parts and single suppliers rather than supplier discovery.

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?

Gives strong situational context — 'Most space hardware is made to drawing by contract manufacturers that have no product catalogue; this is how to find them' — which tells the agent exactly when this tool is the right approach. It does not, however, name alternatives (e.g. list_categories or search_parts) or state when not to use it.

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