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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so the safety profile is covered. The description adds real value beyond that by disclosing the return shape (slug, URL, date, pillar, summary, and the CSV files behind charts) in the absence of an output schema. It does not discuss rate limits or result ordering beyond "best matches."

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 dense sentences with no filler. The capability statement is front-loaded and the follow-up routing detail is appended, so an agent gets scope first and navigation second.

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 carries the burden of describing results and does so concretely, including the slug handoff to get_article. For a three-parameter, read-only search tool this is sufficient to invoke and follow up correctly.

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%, so the baseline is 3; the description earns an extra point by clarifying that the single query parameter absorbs many entity types (topic, equipment class, company, tag, series ID) that have no dedicated field in the schema. The limit and pillar parameters are left to 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?

States a specific verb and resource ("Search Open Factory articles") and enumerates the searchable facets: topic, equipment class, company, tag, series ID. It also implicitly separates itself from the sibling get_article by noting the slug "identifies an article for a full-text read."

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 clear context for when to reach for this tool (broad lookup across several facets) and signals the follow-up path to a full-text read via the returned slug. It never names an alternative tool or states an explicit exclusion, so it stops short of full when/when-not routing.

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