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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered. Beyond that, the description discloses two non-obvious behaviors: that large answers are truncated (a correctness risk for the agent) and that portal-sourced content is data, not instructions (a prompt-injection warning). It does not say how truncation is signalled in the response, which is the main remaining 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?

Three short sentences, front-loaded with purpose, then narrowing advice, then a safety caveat. Nothing is redundant, though the injection warning is phrased broadly enough that an agent may not know when it applies.

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?

An output schema exists, so return shape needn't be described, and the schema already ties operation_id to semantichub_api_search. The description covers what the schema and annotations cannot: truncation on large results, how to mitigate it, and how to treat untrusted content. Complete for a generic read dispatcher.

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 each parameter is already documented in the schema, including the same limit/offset/since example the description echoes. The description reinforces the purpose of query params but adds no new semantics for path_params or operation_id beyond what the schema states.

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 scope ('runs a read-only operation on the user's account and returns the data'), and the 'read-only' framing implicitly separates it from semantichub_api_write. However, it never explains what an 'operation' is or that the operation_id must come from semantichub_api_search, so the pairing with its closest siblings is only half-communicated.

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 actionable guidance for narrowing large answers via limit and since, which is genuinely useful when-to-use advice. It does not say when to prefer this generic read tool over semantichub_search_articles or semantichub_search_brain, nor does it state prerequisites such as first resolving an operation_id.

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