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

Beyond the readOnlyHint annotation, it discloses that the operation is deterministic, precomputed from filed facts, and makes no model call. It also clarifies the 'NEWLY crossed' condition and the provenance of each alert, which helps an agent trust and interpret results.

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?

Six short, information-dense sentences front-load the core behavior before use case, determinism, and argument formats. Every sentence earns its place and there is no filler or repetition.

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?

For a tool with two parameters, a read-only annotation, and an output schema, the description covers inputs, omission behavior, and output semantics well. The main gap is unclear behavior when `since` is omitted or left at its schema default, since the schema marks it optional but the description implies it should be passed.

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 description coverage is 0%, so the description carries the full burden. It defines entities as tickers, since as an ISO timestamp, and explains that omitting entities returns a market-wide digest. This adds substantial meaning beyond the bare schema, with only minor ambiguity around schema defaults.

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 action—returns thesis-break alerts for a watchlist—and scopes results to entities whose break condition newly crossed since a timestamp. It also frames itself as the primitive behind portfolio watch/email digest, which distinguishes it from broader listing tools. No tautology or ambiguity.

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 concrete usage context: pass the customer's watched tickers and the last-digest timestamp, and the caller formats and delivers. It also explains the market-wide mode when entities are omitted. However, it does not explicitly name sibling alternatives or state when not to use this tool, so it falls slightly short of full routing guidance.

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