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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so safety behavior needs no restating. The description adds useful context about output (XOF always returned alongside the requested currency, a link is produced, availability is reported), but says nothing about pagination limits or result ordering behavior.

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 search axes come first, the return payload second. Every clause earns its place and nothing is repeated from the structured fields.

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 10-parameter, zero-required search tool with no output schema, the description covers purpose, searchable fields and return shape adequately. However, it never mentions that 'site' selects between two separate catalogs (~5 600 FR vs ~2 800 EN books) or that per_page caps at 20 — meaningful constraints an agent could miss.

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?

At 70% schema description coverage the baseline is 3, but the description adds real meaning beyond the schema: it specifies that keywords are matched against titre, résumé and auteur, and that the price filter is a 'fourchette' mapping to min/max. It still leaves the site (fr/en shop), orderby and page/per_page parameters unelaborated.

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 precise verb and resource ('Recherche dans le catalogue d'eglise.shop') and enumerates the search axes (mots-clés, catégorie, fourchette de prix) plus the returned fields. This cleanly separates it from get_book (single record lookup) and list_categories (taxonomy listing) without ambiguity.

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?

No explicit when-to-use or when-not-to-use statement, and no sibling is named as an alternative (e.g. use get_book when the ISBN/ID is already known). Usage is only implied by the available filtering dimensions, which lands at 'implied usage'.

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