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

Beyond the annotations (readOnlyHint, idempotent, non-destructive), the description discloses the important behavior that nothing is persisted here — save_brief with the new `confirm` is what keeps it — which explains why a mutating-sounding tool is marked read-only. It also notes the result includes `changes` diffed against the caller's current brief. The remaining gap is how the amendment sentence is supplied.

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?

It is only two sentences, but they are dense, ungrammatical, and not front-loaded — the core action appears inside a subordinate clause. Brevity is achieved at the cost of parseability rather than through tight editing.

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?

Annotations and an output schema cover safety and return shape, and the description correctly adds the non-persistence rule. Still, for a 2-parameter tool with 50% schema coverage, the description fails to explain the `language` parameter or how the amendment sentence relates to the `brief` payload.

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 only 50%: `brief` is documented in the schema while `language` (enum en/pl, default en) is not described anywhere. The description mentions 'one sentence of the reader's' but never clarifies whether `brief` is the sentence, the full amended brief, or the record to be amended, leaving the required parameter semantically ambiguous.

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?

The description does convey a verb (amend) plus a resource (the brief) via one reader sentence, and it names related siblings (set_brief, save_brief). But the sentence is garbled and back-loaded, so the actual operation must be parsed out of fragments like 'compiled as set_brief does' rather than stated directly.

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?

There is implicit routing: amending differs from set_brief's full compile, and persisting requires save_brief with the new `confirm`. However, no explicit when-to-use / when-not-to-use statement or prerequisites are given, so the agent must infer the workflow chain.

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