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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds real value beyond that: it discloses the conditional `catalog` block that only appears for Reevol Catalog publishers and notes that contact happens via request_introduction with no key needed. It doesn't say what happens for an unknown slug or how large the payload can get.

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?

Three sentences, front-loaded with the core action and return contents, then usage sequencing, then the conditional catalog behavior. Dense and largely waste-free, though the final sentence packs the catalog block, the catalog MCP endpoint, and the introduction path into one run-on that could be tightened.

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 does the work of describing the return payload and flags the conditionally-present catalog block, which is exactly the kind of variability an agent needs to anticipate. It omits error/not-found behavior and any indication of response size, but is otherwise sufficient for a two-parameter read tool.

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 100%, with both slug and lang fully documented including the locale enum values, so the schema carries the parameter burden. The description only implicitly touches parameters ("by slug", and the localized "buyer-facing summary + FAQ" implying lang's effect), adding marginal meaning. Baseline 3 applies.

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 opens with a specific verb and resource ("Fetch a full supplier profile by slug") and then enumerates the returned content (identity, location, HS codes, certifications, trade fairs, export markets, summary + FAQ). It explicitly positions itself relative to search_suppliers, so an agent can tell it apart from the other lookup siblings without opening a 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?

It gives clear sequencing ("Use after search_suppliers to dig into a specific match") and routes the contact use case to request_introduction rather than this tool. What's missing is any explicit when-not guidance (e.g., don't call it for bulk discovery or listing verification), so it stops short of full alternative coverage.

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