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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the description's added value is the publication filter ('only published, open documents appear') and the explicit warning that results may be empty. That empty-result caveat is genuinely useful operational context. It stops short of explaining pagination or how multiple filters interact.

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?

Four short sentences, front-loaded with what is searched and returned, followed by the filter options and the sibling hand-off. Minor redundancy in restating topic/sector as 'slugs' twice, but no filler.

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 a rich annotation set and an output schema covering the return values, the description supplies the remaining essentials: scope, filter modes, the open/published restriction, and the follow-up tool. The one meaningful gap is whether filters combine (AND vs OR) and what limit does, which matters for a five-parameter search 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 description coverage is 100%, so every parameter is already documented in the schema, establishing a baseline of 3. The description reinforces that topic/sector are slugs and that page_url scopes to documents related to a page, but adds no syntax or format detail beyond what the schema provides and never mentions the limit parameter.

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 with scope: 'Search the public documents (PDF files) that this website publishes', and specifies the return shape (document cards with schema.org nodes). It also names the sibling get_document as the follow-up for opening a single result, so an agent can distinguish it from search_content, search_media_assets, and get_document 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?

Enumerates three concrete invocation modes (topic/sector slugs, page_url relationship lookup, phrase query) and points to get_document for the drill-down step. It gives clear positive usage context but no exclusions — it never says when to prefer search_content or search_media_assets instead.

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