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

Annotations already cover the safety profile (readOnly, idempotent, openWorld=false, non-destructive), and the description adds behavior the annotations do not: the last word is prefix-matched, results can be tag-restricted, and 'nothing leaves the server' discloses locality. It does not cover result ordering or pagination, which is a minor gap.

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, each carrying distinct information (what it searches, prefix rule, tag filter, locality, empty-query fallback), with the core purpose front-loaded and 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 no output schema and a partially documented input schema, the description supplies the search semantics an agent needs to call it correctly. It is nearly complete, though it omits how results are ordered and whether the limit defaults to anything.

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 67%; the description compensates by explaining the prefix-match rule for the query's last word and restating the empty-query semantics that the schema also documents. The 'limit' parameter is left unexplained in both places, which keeps this below a 5.

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 ('Full-text search over your personal knowledge base'), which is enough to separate it from kb_get_note and kb_create_note. It does not explicitly contrast itself with the closer sibling kb_list_notes, so it stops short of a 5.

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?

It gives a concrete usage rule — an empty query lists recent notes — which tells the agent how this tool behaves at its boundary and implicitly when it overlaps with kb_list_notes. It never explicitly names an alternative tool or a when-not condition, so it is clear context without exclusions.

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