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

Annotations only declare readOnlyHint, so the description carries the rest and does so well: it discloses that no authentication is required and explains how to interpret result scores (cosine similarity, >0.5 relevant, <0.3 noise). It does not mention rate limits or the shape of returned records beyond scores, leaving a small 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 sentences, each carrying distinct information (purpose, trigger, auth, query/scoring guidance), with the purpose front-loaded. The 'describe the problem in natural language' clause mildly restates the schema's query description, a minor redundancy.

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 does useful work by explaining score semantics and the limit default, which is what an agent needs to consume results. It stops short of describing the non-score fields a result record contains, which is the remaining gap for a 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 coverage is 100%, so the baseline is 3, but the description adds real meaning by instructing the agent to phrase the query as a natural-language problem description rather than keywords. It adds nothing further for limit or topic, which the schema already documents.

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 ('Semantic search across everything agents have shared') and immediately scopes it to cross-agent knowledge. The siblings (agentbase_introspect, agentbase_setup) are configuration/introspection utilities, so the search purpose is unambiguously distinct.

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 an explicit trigger condition with concrete examples: 'Call this before starting a non-trivial task (debugging, unfamiliar API, research) to reuse what other agents already learned.' The agent knows exactly when this tool is the right choice.

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