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

Annotations already declare read-only, idempotent, closed-world, so the safety profile is covered. The description adds genuinely non-obvious context beyond that: the corpus is tiny (~26 items), most records have OCR text plus an AI-generated description, and the indexed language differs from the user's. These details materially change how an agent queries.

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 short sentences, each carrying a distinct operational fact (corpus scope, keyword language, no-arg behavior), with the most load-bearing detail (subset size) front-loaded. No filler or restatement of the tool 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 no output schema, the description should say enough about what comes back; it covers scale and record enrichment (OCR, AI description) but not the result shape or pagination semantics, which matter at limit 15 / max 50 over a 26-item corpus — offset is effectively unusable and that isn't flagged.

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 country/limit/keyword are mostly documented already. The description's contribution is the language rule — French concept keywords regardless of user language — which the keyword schema field does not state and which an agent would otherwise get wrong on an English-speaking user's request.

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?

Specific verb plus a tightly scoped resource: a ~26-item archival-documents subset with named content types (Islamic association reports, flyers, project documents) and geography. That scope statement is what separates it from the many sibling search_* tools, though it never names a sibling directly.

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 two concrete usage rules — use French concept keywords, and call with no arguments to list everything — which is real guidance. But it never says when to choose this over search_articles, search_publications, search_index or semantic_search_*, which is the harder routing decision given 40+ siblings.

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