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

Annotations only declare readOnlyHint=true, so the description carries the rest and does: first-call index build cost, fast subsequent calls, restricted/keyed auth posture, hard result cap, and the fact that caveats are delivered via the response's tool_notes. This is meaningful operational context beyond the annotation.

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?

Front-loads the mechanism and corpora, then return shape, then limits, then latency, then posture and alternatives. Every clause carries information, though the return-shape and limit details are somewhat compressed into a dense block that could be split for readability.

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?

There is no output schema, so the description supplies the return contract ({query, count, results, index} and each result's {type, text, score, metadata}) plus latency and auth caveats. Nothing needed to select or invoke the tool correctly is missing.

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% and the schema already documents both parameters, including the limit default and maximum. The description restates limit's default and cap but adds only marginal new meaning (it does not add query syntax guidance beyond the schema's example). Slightly above the baseline because it frames the cap as a hard constraint.

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 the retrieval mechanism (TF-IDF lexical index, not embeddings) and the exact corpora searched (archived news headlines + pulse-fact corpus), and names the siblings it is not (get_news, ol_filing_search). An agent can distinguish it from every other search tool in the list 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?

Explicitly routes the agent: 'For per-ticker archive reads use get_news; for semantic retrieval over SEC filings use ol_filing_search.' It also states the access precondition (keyed tool, refuses anonymous callers), which is exactly the when/when-not guidance an agent needs.

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