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

Annotations already declare readOnly, idempotent, and non-destructive, so the bar is lower; the description still adds genuine value by noting that search does not advance the unread cursor (a real interaction with receive_unread_messages) and by spelling out asymmetric campaign scoping. It omits result ordering/ranking and any cap on results beyond the limit parameter.

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 tight sentences: what is searched first, then the scoping nuance, then the read-only guarantee. No filler and nothing buried at the end.

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 3-parameter search with no output schema and full annotation coverage, this covers scope, filtering behavior, and side effects adequately. Missing only ordering/relevance and result-shape expectations, which would help an agent interpret hits, especially with a nullable limit.

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 baseline is 3, but the description adds real semantics the schema lacks: campaign_id filters only messages, Board, and file hits while Articles, Parking, and papers remain Space-wide. It also clarifies that omitting campaign_id means the default Campaign, consistent with the schema note.

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 (full-text search) and enumerates the exact resource set covered: messages, Articles, Board labels, Parking ideas, bibliography papers, and file-offer filenames. That enumeration distinguishes it from the list_* and read_* siblings, which are per-resource.

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?

The coverage list makes clear when this cross-resource search is appropriate versus the narrower list_messages / list_papers / read_articles tools, and it explains the campaign_id scoping rule. It stops short of explicitly naming an alternative or stating when not to use it.

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