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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so the safety burden is lifted. The description adds useful scoping (same industry and country) and a result cap, but states 'up to 10' while the schema allows limit up to 25 — a minor tension the agent must resolve — and says nothing about ranking or ordering of the similar results.

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 waste, with the core behavior and constraints front-loaded ahead of the usage examples. Nothing needs trimming.

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?

For a simple read-only lookup with full schema coverage and no output schema, the definition is essentially complete: input, scoping, result size, and use case are all present. The only small gap is the 'up to 10' vs. limit-max-25 discrepancy and no note on how similarity/ranking is determined.

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 slug, lang, and limit are all documented in the schema and the baseline is 3. The description only reinforces that slug is a single reference supplier; it adds no semantics for limit or lang beyond what is already structured.

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 ('Given one supplier slug, return ... similar suppliers') plus the scoping constraints (same industry and country) and result cap. An agent can tell this apart from search_suppliers or find_suppliers_by_country without opening any schema.

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?

Provides concrete usage contexts via example questions ('what are alternatives to X?', 'who else makes similar products in [country]?'), which clearly frames when to reach for it. It stops short of naming sibling alternatives such as search_suppliers or find_suppliers_by_country that could also answer 'alternatives' queries.

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