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

No annotations are provided, so the description carries the full behavioral burden. It does not state that this is a read-only operation, does not describe the return structure or pagination, and gives no auth or rate-limit context. It only lists the metric types, which is content rather than behavior.

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?

Two short sentences, front-loaded with the concrete list of returned metrics and followed by the use case. No filler or redundancy, though it is terse enough that it forgoes any structural cues about scope or limits.

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 simple one-parameter read tool with no output schema, the description compensates by enumerating the returned metrics and their time span. Nothing essential for correct invocation is missing, though the absence of any output-shape or historical-window detail keeps it from being fully self-sufficient.

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 100% for the single 'symbol' parameter, so the schema already documents the ticker format and example. The description adds no syntax, format, or scope detail beyond what the schema provides, making the baseline 3 correct.

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?

Names a specific resource (historical valuation metrics) and enumerates the exact metrics returned (P/E, P/B, PEG, EV/EBITDA) over a multi-year window. This is clearly more than a restatement of the name, but it does not distinguish itself from siblings like get_intrinsic_value or analyze_stock, which occupy adjacent valuation territory.

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?

Provides an implied use case ('utile pour évaluer si une action est chère ou bon marché par rapport à son historique'), which tells the agent when this tool is relevant. However, it offers no explicit alternatives, no when-not guidance, and no mention of how it differs from get_intrinsic_value or analyze_stock.

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